Univention Corporate Server 4.0 erratum 42 (bugfix)

This update addresses the following issues:
* LDAP base DNs with uppercase letters caused synchronization rejects.
* GPO Security Descriptors can now be synchronized between OpenLDAP and
  Samba Directroy Service. By default this is not activated, an upcoming
  errata update for UCS@school 4.0 will make use of this feature.
* Ignore cn=Subschema and warn if listener didn't pass entryUUID