QmlDesigner: Move currentState to AbstractView

Change-Id: I3252d85dceff606c85898895e91b7e955441033b
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
QmlDesigner: Rename scenePos in scenePosition

And change it to QPointF.

Change-Id: I24c6238eb2c415296b4621b7aa0ec06d85293cb7
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>