Refactor handling of Actor/Material OpenGL resources, to avoid crash.
Create rudimentary camera controller window in GLViewTools module
Start refactoring camera control window into new SceneWindow module
Improve signalling in CameraControl
Remove old CameraControl from GLViewTools
Remove 3D viewer module, obsoleted by SceneWindow module
Refine Camera Control behavior
(Rotation still needs work...)
Update camera when closing and reopening Camera Controls
Display micrometers better in Camera Controls
Start trying to apply selection tutorial to scenes and cameras