Adds modelWorld and View Matrix and shader uniform.

- rebased on latest develop
- Allows use of world uniform
because you want to be able to give it transformed BBox, not local bbox.
see https://github.com/cedricpinson/osgjs/pull/131/files?diff=split&w=1#diff-ece7c42cf3b8e9cbd8392b2b82e1e6ebR635