Merge pull request #57 from synopia/master

Icons angepasst
layout changes
increased width for event text
increased event text width
Improved Layout

* fixed problem with menu layout and usergroup view
changed layout

* header text links to the root page now
* social icons are hidden in mobile view
* changed margins and paddings
Admin can now delete User und UserGroups
enabled usergroup admin view
added ical link
Issue #60: X-Frame-Options im embedded controller korrigiert