* Drop obsolete PlaylistView.
Added TomahawkUtils::Queue enum.
* FlexibleView is becoming a ViewPage wrapper for ContextView.
Adapt to new FlexibleView API.
Don't replicate so much of TrackView's API in ContextView.
* Use existing 'changed' signal in PlaylistView.
Emit 'modelChanged' when underlying model changes in TrackView.
* Renamed FlexibleView to PlaylistViewPage.
Added ContextView::setTrackView, allowing you to replace the TrackView with your own implementation of it.
Inbox needs to set its own TrackView on ContextView.
Use ContextView's wrapped modelChanged() signal in PlaylistViewPage.