Add two networks, add IPv6 entries for synIRC

Apologies for not making these changes seperate pull requests, this is my first pull request and I'm still figuring things out about Git ;)

I added two networks: Anthrochat ( http://anthrochat.net/status/ ) and Furnet ( http://furnet.org/ ).
These are two medium-sized IRC networks tailored at the on-line "furry" community.

I also added addresses of IPv6-compatible "Full Link"-servers to the synIRC entry.