merge master into webdav-injection

core/css/mobile.css

lib/private/connector/sabre/file.php

lib/private/files/type/detection.php

lib/private/group/group.php

lib/private/group/manager.php

lib/private/helper.php

lib/private/l10n.php

lib/private/mimetypes.list.php

lib/private/user/manager.php

ocs/v1.php

search/css/results.css

tests/lib/group/group.php

tests/lib/group/manager.php

tests/lib/helper.php

tests/lib/user/manager.php