more admin page splitup improvements

* bump version to ensure tables are created
* make updatenotification app use settings api
* change IAdmin::render() to getForm() and change return type from Template to TemplateResponse
* adjust User_LDAP accordingly, as well as built-in forms
* add IDateTimeFormatter to AppFramework/DependencyInjection/DIContainer.php. This is important so that \OC::$server->query() is able to resolve the
constructor parameters. We should ensure that all OCP/* stuff that is available from \OC::$server is available here. Kudos to @LukasReschke
* make sure apps that have settings info in their info.xml are loaded before triggering adding the settings setup method