Blender Git Loki

- when not F10->"Ray" option is set, materials with "Ray Transp" will
render solid now (no alpha).
- This gives nicer previews, but also makes envmaps look better, since
environment maps are rendered without raytracing
- I decided not to raytrace envmaps mainly because of speed... if you use
environment maps you want something quick... otherwise just use ray_mir
material here!