D4911: add Baloo DBus signals for moved or removed files

[Matthieu Gallien]

mgallien added a task: T4931: Incremental changes from Baloo (new tracks, 
modified tracks, removed tracks).

REPOSITORY
  R293 Baloo

REVISION DETAIL
  https://phabricator.kde.org/D4911

To: mgallien
Cc: #frameworks