improve performance, make it more SORMish re #5230

git-svn-id: svn://develop.studip.de/studip/trunk@32992 c5b85792-5220-0410-ad23-ed5b6b8ad999
remove obsolete class re #5230

git-svn-id: svn://develop.studip.de/studip/trunk@32993 c5b85792-5220-0410-ad23-ed5b6b8ad999