D17629: Add method to BackgroundChecker to add word to session

[Ahmad Samir]

ahmadsamir added a reviewer: sandsmark.

REPOSITORY
  R246 Sonnet

REVISION DETAIL
  https://phabricator.kde.org/D17629

To: ahmadsamir, davidedmundson, cullmann, sandsmark
Cc: kde-frameworks-devel, michaelh, ngraham, bruns