Blender Git Loki

- Recursive environment map render

Multiple environments now can be rendered in one pass. Previously the other objects with environment maps didn't show up in a reflection. Like this:
http://www.blender.org/bf/dep.jpg

By default, Blender renders now this result:
http://www.blender.org/bf/dep0.jpg

For a further 'recursive ray-tracing effect' you can give each EnvMap texture a higher "Depth" value. Here is a result with depth set at '2':
http://www.blender.org/bf/dep2.jpg

Related new options:
- in (F10) DisplayButtons, environment map rendering can be turned on and off.
- in EnvMap texture buttons you can free all environment maps
- Environment map sizes are also reduced with the (F10) 'percentage' option.

Tech note: with this commit the VlakRen struct has on *ob pointer!