D7676: Added openService() method to KRunProxy

[Mladen Milinkovic]

maxrd2 added a dependent revision: D7648: Fix ksysguard not starting on 
plasmoid click.

REPOSITORY
  R296 KDeclarative

REVISION DETAIL
  https://phabricator.kde.org/D7676

To: maxrd2, davidedmundson
Cc: broulik, #frameworks