Some source strings are `const char *` and we don't have an alternative
`str` type pointing to a const buffer. Strictly speaking some buffers
aren't even char buffers, yet we use the `str` type to manage them. This
eliminates the need to explicitly cast every usage.

Change-Id: Ifd3cdd3d400fc483e6c488a95e9381938e63cc7f

Change-Id: Ib64e36db7ccccda83a84d36f716d13906d098946

Change-Id: Ib3ad0c63d751cc795bff48e1b9fc81f88c7de9d0

Change-Id: Idf211e3e73593e0b8213d516446d33d95e866db1

... which don't know about __attribute__((access))

Change-Id: I30a31d03ab492e0e9cd2f7e59a292ad7ba9b184e

Change-Id: I896dc74ced7df96d4f5fd06061a20fae2ab98274

... and use them in a few places where it makes sense

Change-Id: I849f2841990808de6f697c92e2760645286dacca

for #1690

Follow up to 37d7762f

Change-Id: Id58204db5a733b3d821cbef855fac72451484b41

Change-Id: Ie4c94640f7b59fa6b6cbed1082a6be6c3a1490e5

Change-Id: I330d5137d38017641bdda71e8bd014c358c432fb

This makes it possible to use buffers returned by GString
interchangably.

Change-Id: If15a5c0be2743dde7230b2f3d3ca6780d633622b

Complete overhaul of the codec handling code:

*) obsolete flags `asymmetric codecs`, `symmetric codecs`, `reorder
codecs`

*) support proper codec offer/answer

*) split codec manipulation (strip/offer/accept/etc) into separate
functions for clarity and better code maintenance

*) fully update codec handlers in both directions after an answer

*) explicit allocation and handling of codecs and payload types in a
codec_store object

*) improve codec matchup logic during answer

*) more explicit handling of supplemental codecs (CN/DTMF)

*) remove now obsolete hacks for handling certain use cases

Change-Id: I996705ba8fe339524c2f70e6bb0fd854f9a1f4fb

This allows these macros to be used in regular assignments and not just
initialisers.

Change-Id: I66ed96192c16ef777959fd9e40302db2786b6545

Change-Id: I57246916f472d4d2f61611c401e2324b97329bb6

This makes the type in line with string(3) functions and eliminates some
compiler warnings.

Also update the related bencode data type.

Change-Id: I7ef4024f4b5a0f737b3dbe03bcd078032395bce6

This leads to unaligned memory access, so remove it.

Change-Id: I4d7c6d42a58f20a0d69fbb933cb925e3bcf0c695

If the length of the string is zero, the pointer to the buffer may be
null. ASAN flags these as invalid/undefined, so don't do that.

Change-Id: Ic55498465c53a78e1bd44c42d1a60f9bd3336473

closes #1021

Change-Id: I0354e4b357c159893a91ef9c96560f99a12778d2

Change-Id: Ifaac7f85a5ab3515d95e72b6ee640c9e865cf219

Change-Id: I4b1c23d9a08b68bd722e14d7077198ddbaefc2e0

Change-Id: I70d65bc519ca82fe4e464946beb154e0b5031c0d

closes #775

Change-Id: Id54309bf0920e731ad42fb09b078580090f6f82e

Change-Id: I2ffa4da4be3a05f043e7991612bbb37d8102d91a

Codecs that were implicitly accepted for transcoding had no option to
set their parameters (such as bitrate) for encoding. The codec-set
option adds this.

fixes #681

Change-Id: Ib238eb73a507af168c366579abc80da07250fe88

also fixes an off-by-one bug of the original str_str()

Change-Id: Ic781f963eea90e3d29ed856c8b00f150eedb139b

Fixes AMR transcoding. Some features yet unsupported.

Fixes #498

Change-Id: I1075a539a7a7dab9106df9ef49b8bda2484b97ec

closes #472

Change-Id: I10dc4aa8baadfc4c3d5ef5514e47fecc4bf2f10e

Change-Id: Ifac093cfba74a7cfdf1ba22209d608e04fed8c10

Change-Id: Id5cf290cc9d044716b5f55cf416dc40b87f23f24

Change-Id: I0fb541215a1bb1a248693a6258e953827258b7ec

fixes #374

Change-Id: Ibfe89b7804183ef04eba39d29e01b70160f7c264

s/paramter/parameter/
s/fowarding/forwarding/
s/readabilty/readability/
s/recieving/receiving/
s/genrated/generated/
s/parametes/parameters/
s/existance/existence/
s/shouldnt/shouldn't/
s/seperate/separate/
s/neccessary/necessary/
s/occurence/occurrence/
s/timout/timeout/
s/ouput/output/

Change-Id: I4403eb54130f3c114d7881054abfdfc8223b5bf2

Change-Id: I8e2b47bf34206ed5cc369649bf8ef875ac271169

Change-Id: I6a5c26b6e0c856b1930273c37b35020dd48c6505

Change-Id: Ifc164f5737decefef2463af57d75f717b97e169b

Change-Id: Icdc97a9dc849bba6ba6add12d0bdd17f8b7712cd

Squashed commit of the following:

commit 1af3efd464
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Mon Nov 7 11:10:22 2016 -0500

    save and restore call recording status to/from redis

    closes #254

    Change-Id: If3cd34fcfd64fa8164521a86eb1d1aa0eb327f3b

commit 460053a231
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Nov 4 14:09:08 2016 -0400

    restore libcurl build dependency

    Change-Id: Ia853f928caf9e443bb69c4015cbba805e6d24153

commit 5f5fd88fde
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Nov 4 11:22:27 2016 -0400

    ensure we are always decrypting SRTP when recording

    Change-Id: I2b75afefcadc55ebf1bf6a19a983134c87c41602

commit 69b4e9fa88
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Nov 4 09:56:47 2016 -0400

    remove redundant ng result=ok logic

    Change-Id: I84d7245f52dc12a4002b4dd2b736afea9ae733fa

commit 411213dd3d
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Nov 3 16:04:54 2016 -0400

    support the `start recording` command message

    Change-Id: I316e90fd3fe34f01b20826936ef620bcff785397

commit ae1910c68d
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Nov 3 15:01:57 2016 -0400

    move logic for `record call` flag to where it belongs

    Change-Id: I65a3b5d62f4360df4251faea1339b5a6355c0e6d

commit 217008d572
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Nov 3 12:49:48 2016 -0400

    support combining streams into one pcap in reference scripts

    Change-Id: Id82936ae7ef1b406acf3b4d3429ecc1cb6e2356e

commit 3fcafd9275
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Nov 3 11:40:00 2016 -0400

    output additional details to metafiles

    Change-Id: I0539a0617aff51c9c499bbd9586d61c7e7ca7e7c

commit e81f413f3b
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Nov 2 16:18:28 2016 -0400

    globalize kernel access variables

    Change-Id: Ie07e0ebb8705189c8b1e49f596080ff8bcaef64f

commit 5e74609c7c
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Nov 2 12:20:55 2016 -0400

    duplicate error messages to stderr when in foreground

    Change-Id: Iaf9d8d1392946046846cb6f2c0fb928a96893911

commit 032077bed4
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Nov 2 11:38:22 2016 -0400

    eliminate dummy virtual function

    Change-Id: I7cc2596f31350bf0d39253b3bd7e9fe1cec2b92d

commit 9177effc4e
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Nov 2 11:30:58 2016 -0400

    clean up recording code related to ng interface

    Change-Id: I69c6d953f8467e5154f000979c94f2dc3a79918a

commit ac0ec6a5e7
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Nov 2 10:57:15 2016 -0400

    output before/after sdp to metafiles

    Change-Id: I1d3177e40591d6b4c4789eb6e18132743a9eda45

commit 68b27fa964
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Nov 1 15:40:20 2016 -0400

    fix header length problems

    Change-Id: I896453f72df3ba146251f5d82ca1d02dd0ad08e9

commit ebbd942ad0
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Nov 1 14:14:08 2016 -0400

    support writing pcap files in reference intercept script

    Change-Id: I53502ba416426e9012a68c35cdf4b457d7c3eb69

commit fe82efa40a
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Nov 1 13:35:47 2016 -0400

    ensure we never make any calls that might sleep when holding locks

    Change-Id: I1ce6aeced1f61715374b80f6fb1fbeafc987ae7f

commit be5316e804
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Nov 1 13:08:19 2016 -0400

    fix math in auto_array_find_free_index

    Change-Id: I39c786b03dbafe59b88a1945ac27964c3852c9eb

commit 183d4939ca
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Nov 1 11:41:47 2016 -0400

    adding rudimentary lock debugging

    Change-Id: Iff541c58e5ea4c3fc2ec16e93396148f935bc4f3

commit 51a75c5022
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Mon Oct 31 14:35:17 2016 -0400

    handle read errors in reference intercept script

    Change-Id: I047d763dbd498026a0d8db24c5532155c75fd6e6

commit 69a460de08
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Mon Oct 31 14:34:54 2016 -0400

    changed locking semantics to avoid proc_clear deadlock

    Change-Id: I70dbc07aa8af7b9860beca86b4b82d8180d8a0ae

commit 62eae1459a
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Mon Oct 31 12:50:26 2016 -0400

    additional debugging

    Change-Id: I81c93c2dd9007ed6a0d6e0b147de0deb44b7b023

commit fd36794740
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Oct 28 12:07:25 2016 -0400

    adding reference implementation using inotify

    Change-Id: Ibec73bdc4c7a576e4beaf5e749567dd2508be4df

commit f8fde6cc73
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Oct 27 15:55:10 2016 -0400

    add stream info to metadata files

    Change-Id: I200df14a3e35c2c0077866444b96692de4303761

commit 5a8b4dd156
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Oct 27 14:47:49 2016 -0400

    pass intercepted packets to kernel and tie in kernel idx

    Change-Id: I33ff297c4a66276b05d0e5d537b0281f27116243

commit 0c0b97ea39
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Oct 27 12:29:02 2016 -0400

    abstractize fake packet header and support ipv6

    Change-Id: I6c1ad1cccad306f3d306fb3387efcb033a3574b2

commit e1b648b9ba
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Oct 27 09:32:40 2016 -0400

    support creating kernel intercept streams

    Change-Id: I1f9bdda61af52814f07f765a8b558a7491cfc0b9

commit b6737ec963
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Oct 26 14:46:13 2016 -0400

    get rid of call->record_call flag

    Change-Id: I04dcba49b07fc669b0bb4bcea8ccc2b52cb76e02

commit 6ed362c120
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Oct 26 12:53:04 2016 -0400

    add recorded call to /proc

    Change-Id: I1fe64b9fb8fe3604bb7d432899c43e3e37ea6a4f

commit 62d2508ecf
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Oct 26 10:10:05 2016 -0400

    simplify some code

    Change-Id: I2a27400e91f58aa8ea20d3e610a7509d2e9a0dfc

commit 0c811a8e91
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Oct 25 16:12:59 2016 -0400

    create separate ../tmp recording dir and clean up duplicate code

    Change-Id: I94e0c19a1e8fed5a30212b79930987333f5e6786

commit 16592a9230
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Oct 25 11:26:54 2016 -0400

    remove explicit libcurl dependency

    finally properly fixes #251

    Change-Id: I3feafe2d0086f6dd789175e6ec0079c54edd487a

commit c78ac5bbb7
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Oct 25 10:48:50 2016 -0400

    abstractize recording cleanup routine

    Change-Id: Ib9fc46542f273bab53f611a1456f02d67edfc966

commit d8358c9a2c
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Oct 25 10:07:44 2016 -0400

    use shorthand for function pointers

    Change-Id: Idf43949e20281a10317e22a5b68a6d133e398bd4

commit 9417437c10
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Mon Oct 24 15:31:56 2016 -0400

    abstractize individual recording functions

    Change-Id: I0974696b6bb361fce39b24d6be91b5c052ee2b14

commit eb631cd876
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Mon Oct 24 11:54:42 2016 -0400

    abstractize call recording mechanism

    Change-Id: If8672051227944544d9cf916d359c5db67235e3e

commit 70797ceb8f
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Jul 14 11:25:05 2016 -0400

    combine two mallocs into one for user-generated packets

    Change-Id: I585d129f10d379a5cb853382773f91a7cec9a98d

commit f62f71cee4
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jul 13 14:22:18 2016 -0400

    check for and avoid /proc file name collisions

    Change-Id: Ie9eb9ceef8f32de8aba816f0121e768c57fa7402

commit ec6b3d22fc
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jul 13 11:02:04 2016 -0400

    implement free list

    Change-Id: I3e7dc2325c937923d19ce6000f2cf1c011e51037

commit bd75a1cf25
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jul 13 09:30:36 2016 -0400

    make number of packets retained per stream configurable

    Change-Id: If1c87f80dd7367cbc274d13c15f94836ef9c8cb1

commit de259c3d64
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Jul 12 15:15:01 2016 -0400

    facilitate passing packets from kernel module out to userspace

    Change-Id: I2317a007084a1718e185ba04632c53a9ebe5f29d

commit 3aa88716fb
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Mon Jul 11 10:45:10 2016 -0400

    restructure calls and streams to global arrays

    Change-Id: Icfca615b21f2e51b1abda4422c4eeb8f4ac70a9b

commit 6cf9980f3e
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Jul 8 11:53:32 2016 -0400

    implement poll/select mechanism

    Change-Id: Ic10c017250f0991f691a887b078e80f694bba853

commit d95829e07b
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Jul 8 10:44:38 2016 -0400

    discard new/old packets as required

    Change-Id: If73ce77dcbc24addb6ce0931b90de0f5efae9f51

commit be1d769e44
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Jul 8 10:25:38 2016 -0400

    implement EOF for stream readers

    Change-Id: I858dc1fdd7df3b65283e1d96457d87e7452840f5

commit ed2d98d55a
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Jul 7 15:02:58 2016 -0400

    blocking and nonblocking reads - incomplete

    Change-Id: I7cbfb09507ad8726773d6a28ddb98d5981decd04

commit 246709c7f4
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Jul 7 13:55:41 2016 -0400

    rudimentary packet reading/dequeuing

    Change-Id: I1a924e5cb2ef4e4f16aeff1f1dd90d0746f91da5

commit 4277493949
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Jul 7 12:40:31 2016 -0400

    use kzalloc where appropriate

    Change-Id: Icd6a109a69ab4f6dc9f7d35fd9e8fc9127f8e7e0

commit 5b07819217
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Jul 7 09:07:54 2016 -0400

    more module referencing

    Change-Id: I2e34fe74f2edef9170a4558f6a24394240966d79

commit 1d8268f636
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jul 6 14:56:42 2016 -0400

    store delivered packets in queue

    Change-Id: Id349b75e06f9dd77c884196b7726027ac5cab7ae

commit 23c6a53f94
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jul 6 14:21:27 2016 -0400

    implement call for packet delivery

    Change-Id: Ibeb815bf2fedfdd644d324c65b58a24871d47d4a

commit c8fd855f32
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jul 6 10:28:18 2016 -0400

    automatic cleanup of objects upon free/delete

    Change-Id: If244905e2d074f491229316f3305c9b0b1451792

commit 282ef603a8
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jul 6 09:47:29 2016 -0400

    unify read/write functions

    Change-Id: I78b0dd05cd730e16655034994c74cbe23be23fce

commit e74c62cc6f
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Jul 5 15:36:00 2016 -0400

    rename _push to _put and _hold to _get

    Change-Id: I9b0ff5038b541bd3cfb961657c15a26f26ccdfb2

commit d71ce17529
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Jul 5 15:33:07 2016 -0400

    support creation and deletion of streams

    Change-Id: I7df05d232b5971c54ca50adce8144b5f1646fba0

commit 8be4e2c7c4
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Tue Jul 5 11:54:39 2016 -0400

    create functions for redundant code

    Change-Id: Id3772f12294ee9891d22d833274e5935814cae0b

commit 47ce4ca8f5
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Jun 30 12:12:19 2016 -0400

    support creation and deletion of calls objects

    Change-Id: Ie5f9aa978bac21fc30909f14d6a438494848dfd5

commit 8dab54209d
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jun 29 14:20:23 2016 -0400

    create /proc/.../calls directory

    Change-Id: I682a4bf23edbb72772d64963e3ba2cab2a521ff4

commit 1401ae8db5
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jun 29 14:02:11 2016 -0400

    rename kernel message enum

    Change-Id: I45d7aeae43df1fe6ecd6b6965dbd6ba7e7b715d8

commit ce44ff0dbe
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Jun 29 14:00:32 2016 -0400

    convert kernel message data to union

    Change-Id: I7cfd9fe81623efae0a828ba457aa0a4b1380ff03

Change-Id: I4bb0b7f6d29c1c7a2144e4735ed59f3dc0e37094

We want to be able to associate call files with a call without the
presence of identifying metadata within the metadata file. To accomplish
this, we prepend the call-id to the start of the pcap recording files
and the call metadata files.

Even though call-id is supposed to be unique, because of paranoia we
keep some of the random affix hex string, but we reduced it down to an
8-byte random value.

Also, some minor argument ordering and name refactoring for random
string generation functions.

File system code is now in fs.{h|c}. This includes:

    - spool directory setup
    - metadata file management
    - pcap file creation and writing

Random hex string generation is now in str.h.

Change-Id: Ide82c1c882589f99e10cce28646b835ae3d8831c

This brings master up to date with branch `rfuchs/socket-rework` at
commit `b1bcc096b7`. The branches have diverged too much for a proper
merge, so this is a manual (squashed) merge.

The old master before this merge can be found in branch
`old-master-before-socket-rework` (commit `82199216b2`).

This is a complete rewrite of all socket handling routines. The most
important functional change is that sockets aren't indiscriminately
bound to INADDR_ANY (or rather in6addr_any), but instead are always
bound to their respective local interface address and with the correct
address family.

Side effects of this are that in multi-homed environments, multiple
sockets must be opened (one per interface address and family) which must
be taken into account when considering RLIMIT_NOFILE values. As a
benefit, this change allows rtpengine to utilize the full UDP port space
per interface address, instead of just one port space per machine.

The socket abstraction also makes it possible to support RTP over TCP in
the future.

Change-Id: If6cf4f42136229490186d2d2482fb4fc140c2b53

*  0 will allow 0 sessions (e.g. can be used for draining rtpengine)
* -1 will disable the feature and will be treated the same way as if
MAX_SESSIONS variable has not been set via configuration file
(or has been set to -1 in configuration file)
* < -1 will not be taken into consideration
* add check for minint range also

RTPengine starts with 1048575 (1<<20 - 1) maximum open files limit.
Make the maximum number of open files configurable using
"rtpengine-ctl set max-open-files 'open_files_num'" command.
Update utils script.

fixes #118

use via-branches to predict different destinations for branched SDP
offers without knowing the respective to-tag ahead of time.

Squashed commit of the following:

commit 0e81dc9828
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu May 21 11:06:15 2015 -0400

    fix segfault due to missing reverse tagging

commit cd7a26314b
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu May 21 08:57:42 2015 -0400

    support branched offer with previously unseen to-tag

commit 77da616dd2
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Apr 29 11:15:37 2015 -0400

    implement via-branch handling

Squashed commit of the following:

commit cca40e8e31
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Feb 12 10:17:51 2015 -0500

    support per-payload-type stats in kernel module

commit dcc0dc0002
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Feb 11 12:14:44 2015 -0500

    count unknown rtp type as error

commit 941bde0df5
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Wed Feb 11 12:01:55 2015 -0500

    use the list of rtp formats from the m= line

    This avoids dynamically altering the rtpstats hash table and makes
    keeping packet stats lock free.

commit 9150fed671
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Feb 6 15:06:04 2015 -0500

    fix and simplify rtpmap hash table

commit 1f73741cbf
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Fri Feb 6 13:56:07 2015 -0500

    MT#9935 understand, learn, remember and report RTP payload types (codecs)

commit b0d690837c
Author: Richard Fuchs <rfuchs@sipwise.com>
Date:   Thu Nov 20 13:36:25 2014 -0500

    parse a=rtpmap attribute

adds CLI option --sip-source to restore old default, and adds
new flag "SIP source address" to achieve the same on a per-call
basis