Improve ALIAS, CNAME, DNAME & PTR record FQDN validation

base64.decodestring was deprecated and removed in Python 3.9 in favour of
decodebytes (See https://bugs.python.org/issue39351 )

cc #84 #628

Use fqdn package to help verify if the record value is really valid.

The original behavior will treat value like `_.` or `.` be a valid
record, which is strange, and the real world may not have those use
cases at all.

The RFC documents are pretty long, as I didn't read them all or enough
to tell should it be valid or not by the spec, so I opened issue #612 to
discuss this case and got a positive response from the main maintainer
to have the change.

Close #628

PowerDNS: Support pre-release versions

This commit strips any superfluous -alphaN (or beta or rc) from the
version number's minor number so it can be cast to an int. This will
allow octodns to sync to/from PowerDNS pre-releases.

Fix name length validation

Closes #626

Add CAA record support to AxfrSource/ZoneFileSource

v0.9.11 version bump and CHANGELOG update

MANIFEST.in: Add test data

Add support for Gandi LiveDNS

exception

ALIAS records only allowed at the root of zones

Add support for zones aliases

comment

there is no changes in the parent zone

type specified in its data