Univention Corporate Server 4.0 erratum 87 (bugfix)

The following issues are addressed by this update:
* The appearance of the search and advanced search button has been adjusted.
* The module cache is cleared now with the internal registration mechanism.
* Shortened the description for the 'Back to search' and 'Save changes'
  buttons to 'Back' and 'Save'.
* A popup notification about automatically set default values was displayed
  for values which were disabled by the selected options. This has 
  been fixed.