Merge pull request #14705 from rullzer/avatarcontroller

core/application.php

core/avatar/avatarcontroller.php

core/avatar/controller.php

core/routes.php

core/templates/layout.user.php

lib/private/avatar.php

lib/private/avatarmanager.php

lib/private/helper.php

lib/public/appframework/http/datadisplayresponse.php

lib/public/iavatar.php

settings/templates/personal.php

tests/core/avatar/avatarcontrollertest.php

tests/lib/avatar.php