Adding ability to include named anchors for form_group() #2

Added ability to have an before each so as to allow linking to a page#foo when directing users to upload their user picture or whatever. I think this is really important for usability as the user account page can get rather long, and for the old folks who can't use the Internet that well, this is helpful.

Also, included a change to the user.module to write out a named anchor for the user picture as an example.