Univention Corporate Server 4.4 erratum 494 (bugfix)

This update addresses the following issues:
* The Ad Connector is now able to sync kerberos hashes from the
  Active Directory to the UCS LDAP-Server. This can be enabled by
  setting the new UCR variable
  connector/ad/mapping/user/password/kerberos/enabled=true
  If this Variable is not set, the hashes will not be synced.
* When syncing group members, the AD Connector now only
  adds/deletes the edited members instead of replacing the
  whole list of members in that group.