* Changed signature-ip to signature-anon

* Changed signature-ip to signature-anon
* Removed the hardcoding of the link parameter ($1), let the message control the destination.
* Removed the hardcoded talk page links. They can be easily re-added if desired, though, and added per-wiki.
* Removed the $3 and $4 parameters
* Fixed wfEscapeWikiText() to do "]" as well as "[", so sigs with "]" won't break links
* Updated a parser test case for the escaping change