[Fluxus] commits

[gabor papp]

> * fixed bug in save-primitive for indexed polys as .obj
> * added tools for evaluating polygons - these should eventually work on
> any type of polygon primitive, they do on most of them now:
>   - poly-for-each-face
>   - poly-for-each-triangle
>   - poly-for-each-tri-sample (random sampling)
> * added examples/poly-eval.scm which show how to use these things
> * added (rndhemi) and (hrndhemi) for generating points on hemispheres
> (solid or hollow)
> * added examples/occlusion-bake.scm - should work ok, runs in a thread
> for previewing the raytracing
thanks! compiles and runs fine. although i found some mix-up with the 
documentation of the tricks.ss functions and line-intersect.
did you remove poly-type? i haven't used it yet, and these new 
evaluators look very handy. i'm just curious.

best,
gabor