new avatars, complete set re #3464

git-svn-id: svn://develop.studip.de/studip/trunk@26411 c5b85792-5220-0410-ad23-ed5b6b8ad999
refs #3464 : upload retina avatars

git-svn-id: svn://develop.studip.de/studip/trunk@26412 c5b85792-5220-0410-ad23-ed5b6b8ad999