Fixed handling of the display-manager service when changing the remote administration support

- bnc#893606
Added test case
Version and changes
Using function IsEnabled() instead of a variable
Extended test case
Implemented Ancor's recommendations from review

- Using let/allow instead of expect
2 vs 1 -> no Expect in Before
Comments from review
Merge pull request #250 from kobliha/vnc

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

- use #empty?
- use a constant
- dont use #before, set vars explictly
- slightly better tests for wl_key, wl_wpa_eap
Merge branch 'master' into default-route

Adjusted version + changes