The model manager should only set its state to 'Done' if all models are
actually done. When that is the case it can safely emit dataAvailable,
too, freeing us of the need to apply a heuristic to the progress
percentage. In order to have a unified interface to the completion of
model processing an abstract base class for QML and V8 models is
introduced.
Task-number: QTCREATORBUG-11466
Change-Id: Id89c7ef5e24004baab7f37ee5486b69e7611aee0
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
