Shrimp Shader Generator FLTK2 GUI (SVN)

NEW: added the 'array' type, not yet functional

ENH: Escape key doesn't close Shrimp anymore

-Add copy/paste of blocks: second pass after paste the selection is toggle on the new pasted block you can move them by click and drag on one of them.

-Add copy/paste of blocks: first pass(need to do copy/paste for group and tweak paste location for visiblity ,right now the paste is at the same location of the original copy)

Added lichen on (basaltic) stone example.

-Bug fix on deleting single block after a marquee selection.
-Add some comment in the code

Changed default occlusion map (for depth mapped occlusion) to "".

Fixed xyz/comp problems in helpers header (blame the wous). Added bronze material example network (it expects one of Paul Debevec's envlatl TIF in /tmp/, grace-new.tdl).

Small fixes to some blocks, when renaming pads to more meaningful names, some of the code in the blocks retained older names for variables, with the ensuing chaos that followed.

-Group are part of selectable object in the marquee selection
-Group can be move in multi selection
-Add some comment in the code