Shrimp Shader Generator FLTK2 GUI (SVN)

Tweaked the usage information of all raytracing blocks, and replaced the multiple occurrences of the shadeops (with really large parameters lists, like occlusion()), by a single call, with a macro RAYOPTIONS as argument, containing the specific options for each renderer, where possible, or NOSHADEOP where shadeop isn't available. Tweaked the storage class of the variables, their defaults.