Adaption of FreeCAD to QuarterWidget

-removes all soqtviewer references
-create a quarter adaptor class which implements missing functionality
-adopts freecad code to make use of SoRenderManager and changed View3DInventorViewer  interface

src/Mod/Inspection/Gui/ViewProviderInspection.cpp

@@ -472,10 +472,10 @@ void ViewProviderInspection::inspectCallback(void * ud, SoEventCallback * n)
             }
             else {
                 // the nearest picked point was not part of the view provider
-                SoRayPickAction action(view->getViewportRegion());
+                SoRayPickAction action(view->getSoRenderManager()->getViewportRegion());
                 action.setPickAll(TRUE);
                 action.setPoint(mbe->getPosition());
-                action.apply(view->getSceneManager()->getSceneGraph());
+                action.apply(view->getSoRenderManager()->getSceneGraph());
 
                 const SoPickedPointList& pps = action.getPickedPointList();
                 for (int i=0; i<pps.getLength(); ++i) {