Adds recalculation of dropdown position each time

This avoids multiple issues like when an inserted/removed node changes the height of the page.
Merge branch 'master' of github.com:WoltLab/WCF
Updating minified JavaScript files
Mobile optimizations
Merge branch 'master' of github.com:WoltLab/WCF
Improved mentions
Updating minified JavaScript files
Preventing regression of quote bug
Merge branch 'master' of github.com:WoltLab/WCF
Updating minified JavaScript files
Fixes one part of mentioning issue in IE
Updating minified JavaScript files
Temporarily disabled mentions for Internet Explorer due to a bug
Updating release date
Updating minified JavaScript files
Merge branch 'master' of github.com:WoltLab/WCF
Added missing import mapping in update Beta 5
Fixed update SQL
Adds missing JavaScript code to delete user ranks
Fixes issue in UserActivityPointHandler::fireEvents()