More thorough unit tests while I'm in here. Ended up doing some hacks/monkey
patching of DSFMonitor as the client library's object doesn't seem to be fully
functional/useful and has inconsitent behavior.
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.