Univention Corporate Server 4.1 erratum 199 (bugfix)

This update addresses the following issues:
* Extended options are now also evaluated for users/user objects.
* The UDM command line tool now supports the use of '--remove' on single
  value attributes. Before '--set attribute=' had to be used.
* Some old code which handled custom attributes has been removed.
* The object class of extended options is now always added or removed to the
  object without the need to change an attribute.
* The extended attribute option to remove the object class if it is no longer
  needed has been re-enabled.
* The attribute sambaPwdLastSet is now set for computer objects while
  changing the password.