Blender Git Loki

Changes to scene updating with set scenes.
The most useful effect of this is that set scenes can take the simplify settings from the current scene (render team doesnt have to worry about animators simplify settings).

details...
- updating on frame change now passes the parent scene to object update function. (this was alredy happening for updating tagged objects)
- set scenes objects update first so scenes can depend on set objects however this only happened at once level, now set scenes are updated recursively, so deepest level is updated first.
- collision objects used to only look through the current scene, now set objects are included.