New diffuse shader, "Fresnel", which using existing fresnel formula.
Since it hilights edges (away from lamp), nice to fill darker parts with
the new layering system.
Weird stuff though;
http://www.blender.org/bf/0001_0040.avi
(Movie disappears in a couple of days!)
Note; for ray-shadow you need to use the Bias, to prevent 'terminator'
problems. I made that option default now.