trimming string to prevent strange sorting behaviours; re #4935

git-svn-id: svn://develop.studip.de/studip/trunk@32156 c5b85792-5220-0410-ad23-ed5b6b8ad999
updated tablesorter to current version; older one sorted ascending and descending into the exact opposite direction; re #4935

git-svn-id: svn://develop.studip.de/studip/trunk@32157 c5b85792-5220-0410-ad23-ed5b6b8ad999