PointPicker: switch dimensions in the UiViewer
Schlegel: only provide edges via indices
* New classes Face and Polytope
* use edges only as integer pair wirhout points array
SchlegelTranformer: use RIF_CYCLIC_NORMAL to get all faces in the correct order for jReality
 * SchlegelView: added toggle button to switch between 3d and schlegel mode
 * Added new event, that represent the change of the SchlegelViewMode
MainFrame: corrected types of the SchlegelView and PointPicker variables
Add appearance to the global root scene and not to a local root scene
UiViewer: use UiState to determine the current active dimension
SchlegelTransformer: 4D case has no easy method to recieve allfaces. Therefore we deactivate it.
Merge branch '3d-schlegelview'