When finished the creation of a PlanarSubdivisionPolygon via double click, the figure is not correctly finalized.

A callback method from observing the event 'EndInteractionPlanarFigureEvent' would be called too early as the bool property "initiallyplaced" is set too late.

Thus the figure is not correctly finalized when the callback is called. This may lead to incorrect evaluation as the last three control-points are not interpolated.