D12662: Add InlineNoteInterface

[Michal Srb]

michalsrb added a reviewer: KTextEditor.

REPOSITORY
  R39 KTextEditor

REVISION DETAIL
  https://phabricator.kde.org/D12662

To: michalsrb, #ktexteditor
Cc: #frameworks, michaelh, kevinapavew, ngraham, bruns, demsking, cullmann, 
sars, dhaumann