Removes MSN Messenger from profile (and a few other places)

Fixes #918. Turns out MSN Messenger was referenced in a bunch of places
other than just the profile (most specifically, the directory and in
multisearch.bml) so this gets most of it, including no longer trying
to import MSN details from LJ when importing from LJ. Tested lightly
but not exhaustively, but it doesn't seem to break anything. (Knock wood.)
You'll need to drop the `htdocs`. These should just be like,

`general /manage/profile/index.bml.chat.msnusername`