Blender Git Loki

- fix for error in octree traverse code, as appeared in sample provided
by Ztonzy. Error happened when:
- ray intersects in first node of traversal
- next ray should intersect in same first node as well
- no other nodes were accessed inbetween
It's a bit hard to explain! But the reason is in the optimize code
in top of ocread() function, where binary XOR magic speeds up. Here
some static variables needed a reset.