refs #2878 : updating header for startup of page

git-svn-id: svn://develop.studip.de/studip/trunk@25669 c5b85792-5220-0410-ad23-ed5b6b8ad999
refs #3218: delete useless and redundant OK-button because the state of the context is always visible now with the context-icon

git-svn-id: svn://develop.studip.de/studip/trunk@25670 c5b85792-5220-0410-ad23-ed5b6b8ad999