Extrude fixing

Made several fixes at Extrude crashes and at parametric modeling propagation, added the MidPlane extrusion that can be changed from the PropertyGrid. Found the reason why Extrude wasn't deactivating and fixed it: the OnDeactivate() from the Action3d base class was disconnecting the Inputs but because this method was overriden in Extrude the inputs were not disconnecting and were sending events to the deactivated Extrude event.

Will continue with fixing the PropertyDialog that shows messages that parameters are invalid. Will also continue fixing the parametric modeling propagation.