Univention Corporate Server 4.2 erratum 75 (bugfix)

This update addresses the following issue(s):
* Objects can now be copied.
* The generation of reports has been optimized.
* The button styling of referenced policy objects has been adapted.
* The <:umlauts> modifier in the templating mechanism of e.g. user templates
  now normalizes all characters.
* Hidden objects are no longer shown by default in
  an multi object select widget.
* A warning is now shown if a user name is too long to be usable for
  a login on Windows clients.
* The LDAP base could not be modified via UMC anymore since erratum 39.
  This has been fixed.