Shrimp Shader Generator FLTK2 GUI (SVN)

Changed LGMarble block to "Others" menu, removed "Stochastic" entry.
Pixie supports the ternary operator, workaround removed for Pixie for RTGlass in the shading models header.
Added inclusion of shrimp_helpers.h to shrimp_extrapatterns.h and shrimp_conversion.h.
Fixed storage class in some of the pattern functions defined in the extrapatterns header, cleaned up this header, removed some unnecessary computations.
Fixed the Voronoi block, since the order of arguments had changed in the shrimp_fractals.h header and this block wasn't updated to reflect this.
Added or extended the usage information for all the committed blocks. Added storage class specifiers for some of the variables in the Karlsruhe/Moscow metric Voronoi block.

Removed the while block (still a relic from the gtk shrimp, and a borked one as well). Updated the matrix blocks, their usage information, and parenting.
Updated the message passing blocks, their usage information, storage class where needed, as well as parenting.

Added storage class where needed for the global variables blocks. Added usage information where missing. Tweaked existing usage information, added information about validity of global variables in the different shading contexts.

Tweaked the helpers blocks, extended usage information. Updated the surface curvature functions in the helpers header.

Removed topolard2d block from Geometric menu. All coordinates transformations are where under Geometric/Coordinates. Fixed shrimp_conversion.h's transformations. Added missing usage information or extended it, for the remaining blocks. Added UND defaults to matrix function parameter for transform block. Pad type parenting fixed where needed.

Extended and added where missing, usage information for the fractal noise blocks. For the 4D noise types, the 4th dimension variable, that defaults to global variable time, now is accordingly of storage class uniform.
Updated the fractal functions header to reflect this change as well.

Small tweak to shownormals block. Fractals will be next.

Updated conversion blocks, the usage information, as well as the vector/normal/point to color conversion, so that results are in [0,1] range as expected.

Renived blend block, mix() block was updated to operate on all types. Other color blocks tweaked, and had usage information updated.

Tweaked the xml blocks usage information, added where missing. Added workarounds for color type step and smoothstep, since i'm told only PRman supports both float and color types, but available RI specs (3.2.1) mention only float type, so in other renderers it'll operate on a component by component basis.
Removed E and PI number blocks, and replaced them instead by a "Useful constants" block, with the values of E, PI, PI/2, 2PI, 1/PI, as defined in shrimp_helpers.h's symbols.