Configuration of remote administration has been fixed to reload/restart services and/or warn user if necessary

- bnc#893606
- According to the bugreport, Yast Runlevel just restarts display manager while it enables remote administration
- I've fixed the behavior in a way that it starts or reloads services as much as possible and if the display manager is already running, Yast warns user to restart it manually or log out and log in again
- Includes a  nice test case

In this case, you are not really checking if ```Service.active?``` has been called. You are using the call to ```Service.active?``` to define in which context you are. What you really want to check is if your are reloading or restarting the display manager.

Am I going too philosophical?