We are going to need the declarative container for the tooltips,
so it makes sense to put this guy in it's own files.
Signed-off-by: Artur Duque de Souza <asouza@kde.org>
setting the mainItem property of a Dialog element, it will create a top level window with that item as the graphicsWidget()
right now it works only with QGraphicsWidget{} elements, Plasma::Dialog will be given the api to make this work with any QGraphicsObject as well.