Shrimp Shader Generator FLTK2 GUI (SVN)

The bake3d block in 3delight doesn't uses channels for $(bakechannel), default to "" here.
Added a comment in the extras header to clear some confusion. The he_torrance geometric self-shadowing/masking function is the full Smith expression for geometric self-shadowing/masking, as used in the He-Torrance model. The Smith function is an approximation as used in the Torrance-Sparrow model. Note that Christophe Schlick has another similar approximation to the full Smith expression.
Added the initial revision of the sampling headers. This has the Schlick, Ward, Ashikhmin-Shirley (all isotropic & anisotropic), and the Phong and Beckmann distributions. Respective blocks for these are included.

ENH: moved OpenGL stuff out of application code

ENH: updated block hierarchy structure

FIX: missing storage type for shader outputs

NEW: array support for block outputs

FIX: comments in shaders

ENH: added missing Atuhors field in the scene; shader properties are exported as comments in the RIB file

ENH: type_extension serialization

ENH: array support in the 'Edit Input' dialog and shader_block structure

NEW: array's user interface in the 'Add Input' dialog