D5115: [Logout Greeter] Properly fullscreen window and don't bypass WM

[Martin Gräßlin]

graesslin accepted this revision.

REPOSITORY
  R120 Plasma Workspace

REVISION DETAIL
  https://phabricator.kde.org/D5115

To: broulik, #plasma, graesslin, mart
Cc: plasma-devel, progwolff, lesliezhai, ali-mohamed, jensreuterberg, abetts, 
sebas, apol