Shrimp Shader Generator FLTK2 GUI (SVN)

Added support for preset AOVs.

Bug: default preferences.xml file didn't include the renderer code

Fixed problem in the Trowbridge-Reitz distribution, using the description from Pat Hanrahan's 1995 course handout.

Fixed typo in Ks in fur block.

Changed default specular defaults for Sig2k fur block.

Fix default viewer vectors in the associated blocks, they were reversed.

Updated renderer definitions to include other display drivers.

Updated Entropy definitions to include more display types.

Added an envlatl low dynamic range version of a Paul Debevec's HDR map (beach) - from www.debevec.org. This should be copied to $HOME/.shrimp/temp/ as of when shrimp runs for the 1st time, to be accessed by all examples.

Added cracked glazed clay example. Note: it uses an environment map that should be included in Shrimp. When it first runs, should be copied to $HOME/.shrimp/temp/ to be accessed by all examples. Going to commit this file to shrimp/examples/ as well.