Blender Git Loki

More render stuff:

- added 'Mapping to" channel "RayMirror", to control mirror with texture
- fixed bug in using mirror-rgb as texture channel... this is cumbersome
because it is abused by Envmap in a not nice way. Fixing the abuse will
cause compatibility errors, which can be fixed when we up release # to
2.32.

- added "Translucency", which is nothing else than allowing another
shading pass for the backside of a face (with normal inverted). This
is interesting for all kinds of situations where you want light from
behind to 'shine through'. Also works to reduce dark areas in
unlighted parts of rendering transparent faces. Light from behind on
transparent red window should make it glowing some, right?!
- added texture channel for this as well

- Reorganized Material Panels to reveil some consistancy where buttons
can be found. Not perfect yet, but at least all options for Shaders and
options for Mirror & Transparency now are together.
This gives some space in Shader Panel for nice expansion.