restructured hook_user to allow easier reuse of buddylists elsewhere

#80116 patch by ankur #26: Prevent the "add user to my buddylist" link from appearing if a request is pending

#80166 by ankur: optional workflow to send request emails to the user who must approve or deny the request to become buddies.

zapping the forked, out of date, untagged CVS version of buddylist. Adding info into the README explaining why.

minor usability improvements; message upon install if profile module isn't enabled and no link to profile pages for users without the view profiles permission

new module: buddylistinvite. This is an implementation of hook_invite. When enabled, this module will make inviter and invitee buddies of each other when the invitee accepts the invitation.

I don't like the term "buddy". I think of this as a contacts module. So now all the "buddy" variations are their own translations and you can translate just those terms to change buddy to contact, or friend, or ferret etc.