by aangel, Dave Cohen: add parameter to event callback.  Otherwise, post-remove events have no way to know which application is removed.

misc comments

deleted some obsolete code

changed _fb_js_fbu param to avoid confict with "fb_..." params from old facebook api.  Still not working on canvas pages though.

Also improved comments to fb_scrub_urls().

by aangel, Dave Cohen: moved fb_user_app table, which tracks users who have authorized apps, to its own module.

#870010 by aangel, Dave Cohen: mechanism to manually link accounts, if fb_user.module is not configured to do so autmoatically.

by aangel, Dave Cohen: stop using authmap table, use new table fb_user instead, for mapping local accounts to facebook ids.

feature #612412 by aangel, Dave Cohen: optionally store user names in human-friendly format.  Also fixes to account create logic.