QVTKOpenGLWidget Rename and other GUISupport cleanups
- Rename QVTKOpenGLWidget in QVTKOpenGLStereoWidget
- Provide a Legacy version of QVTKOpenGLWidget
- Add a QVTKRendeWidget that only wraps QVTKOpenGLNativeWidget for now
- Remove the depreacted module GUISupport/QtOpenGL and QVTKWidget2 and QVTKGraphicsItem which was not deprecated for some reasons.
- Remove the deprecated QVTKWidget and all related classes
Edited by Mathieu Westphal (Kitware)