updated file comments; converted to cp1252; lower-cased null constants (PSR-2); re #4068

git-svn-id: svn://develop.studip.de/studip/trunk@29569 c5b85792-5220-0410-ad23-ed5b6b8ad999
api: fix news return, re #3484

git-svn-id: svn://develop.studip.de/studip/trunk@29570 c5b85792-5220-0410-ad23-ed5b6b8ad999
api: disallow commenting on news with allow_comments = false, re #3484

git-svn-id: svn://develop.studip.de/studip/trunk@29571 c5b85792-5220-0410-ad23-ed5b6b8ad999