Merge branch 'master' into notifications

diff --cc wcfsetup/install/files/js/WCF.User.js
Simple merge

diff --cc wcfsetup/install/files/lib/data/user/UserProfile.class.php
Simple merge

diff --cc wcfsetup/install/files/lib/system/user/notification/UserNotificationHandler.class.php
Simple merge

diff --cc wcfsetup/install/lang/de.xml
Simple merge

diff --cc wcfsetup/install/lang/en.xml
Simple merge

diff --cc wcfsetup/setup/db/install.sql
Simple merge