Supports ALIAS for Dnsimple, Dyn, Ns1, and PowerDNS. Notes added to readme about
some of the quirks found while working with them. TTL seems to mostly be
accepted on ALIAS records so it has been added back, what it means seems to vary
across providers, thus notes.

Fix NS1 provider name

Update example class name from "octodns.provider.nsone.Ns1Provider" to working "octodns.provider.ns1.Ns1Provider".

Update README to include new NS1 Provider

First pass through NsOneProvider

They were working around the lack of class hierarchy, this addresses that by
adding 2 child classes. It gets rid of a bunch of ugly default params and
if-this junk in the main class that was trying to deal with plain & geo records.
Also as a positive side effect it gets rid of some hacks that lived in
Route53Provider dealing with the fact that the old setup couldn't detect going
to/from a GeoDNS record correctly.

Add __main__ calls to main in cmds

Fixing octodns/record.py link

use a percentage of change/deleted records rather than an absolute count

Dyn monitor user agent

Route53 geo conv fixes

Handle Cloudflare not escaping semicolons

readme: Fix link to contributing doc

Fixed broken link to Records Documentation

readme: typos and bad links

Fixes typos in the Supported providers table

Fixes to get a working sdist build

Supported providers readme

DynProvider Traffic Directors want lowercase province without country