Univention Corporate Server 4.0 erratum 95 (bugfix)

The following issues are addressed by this update:
* If host name or user name are too long for the menu labels in the header,
  their length is now trimmed and "..." is shown.
* The positioning of the "back to overview" header button has been adjusted.
* The UMC background image has been adjusted.
* The default search button has been adjusted to be smaller and to only
  contain an icon instead of text.
* The UMC header menus have been adjusted in their positioning on small
  screens and they have been styled with icons.
* The style of modules and module headers has been slightly adjusted.
* The label for module buttons is centered if there is enough space.
* Changed the cursor to a pointer when hovering grid row actions.