Scene browser progress

 From:  okapi
2470.5 
Michael, great to see the progress on the scene management!
Hope to see a beta with this soon.


Some very important questions:

- will the group be recognized as separate layers by Rhino?
- will the layers from a Rhino file be recognized as separate groups?
-will it be possible to export OBJ models that preserve the grouping mode.

These are the most important points that I can think of.