Add properties for test news bidirectional path tracer features
Normalize project names
Change some values to most explicit names
Add code for custom material nodes when material have 'nodetree':
    - you can view the current node panels instead the classic material panels.
    - you can view and select the list of all material node trees in the scene.
Refine code for detect active branch's.
Merge branch 'rc2' of https://github.com/TheBounty/Blender-Exporter into rc2

Conflicts solved:
	io/yaf_object.py
	prop/yaf_scene.py