Shrimp Shader Generator FLTK2 GUI (SVN)

Added Mantra as a supported renderer (to the respective menu entries and renderers.xml - atm duplicated in data/mantra and data/rib). Added some comments regarding RenderDotC status as well. The VEX tags, vex_include and vex_code are supported already, so initial tests and block+headers porting work can start without "unknown renderer" messages.

FIX: fixes in the shader block parser

ENH: first pass to deal with arrays

-logo png format

- Add in preferences : Pixel filter and filter width s ,filter width t parameters
- Add export of Pixel filter ,filter width s and t parameters
- Change color theme of the doc and Shrimp logo: closer to Shrimp color theme

- fix the double display of blocks in the add block menu

Updated some information on the usage for the shadowing and masking functions.

- Change the square size around pad shader parameter
- Test of a documentation system for Shrimp blocks base on xml file information.(will start firefox from the menu help if you don't have it check the doc folder and look for index.html from your browser) the doc it's generate everytime you restart Shrimp to take account your last custom blocks(will put an option later in the preference)
- Correct some syntax on some block that create xslt issues during parsing

Fixed some commit issues, IFD/bgeo/OTLs work thanks to Hans Hoogenboom.

- block property that are also shader parameters will have a orange square.