Item12336: Update docs for Func::addUserToGroup

git-svn-id: http://svn.foswiki.org/trunk@16360 0b4bb1d4-4e5a-0410-9cc4-b2b747904278
Item12310: Update registration documentation

 - new timer added to expire registration
 - other documentation improvements.

git-svn-id: http://svn.foswiki.org/trunk@16361 0b4bb1d4-4e5a-0410-9cc4-b2b747904278