- More profile module improvements:

  + Updated the _user() hook's "$type == 'view'" case to match the
     "$type == 'edit'" case.  That is, both have to return an associtive
     array of the format array('category' => 'fields').

   + Updated the profile pages to group fields by category.  Made possible
     thanks to the above change.

   + Moved logic out of the theme_ functions.