D5153: add a new property in containment, for an edit mode

[David Edmundson]

davidedmundson accepted this revision.
This revision is now accepted and ready to land.

REPOSITORY
  R242 Plasma Framework (Library)

BRANCH
  phab/editMode

REVISION DETAIL
  https://phabricator.kde.org/D5153

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