Blender Git Loki

Orange:
So... now I understand file reading and libraries again, I couldn't leave
it to do a nice optimize step. This commit introduces bsearch() for finding
the elements in the pointer table, while reconstructing links. Tests reveil
a speedup of a factor 2-5 on complex scenes. And since undo uses same
system, quite nice in general!

(Note; speedup sometimes can't be noticed, when a lot of subsurfs or other
displaylists need to be generated.)