freeDNS Dynamic DNS API v2 Support
This adds support for freeDNS (afraid.org)'s DynDNS service's more recent API version, which hosts a IPv6 only endpoint, allowing for more reliable IPv6 DynDNS updates.
I had trouble getting IPv6 to update properly using the V1 module IPv6 implementation. Instead of trying to fix the problem, I figured just implement the latest API. The V1 API implementation is left untouched for backwards compatibility.
Tested working for both v4 and v6.