Log Message:
Updated Cg-compiler to latest release, 3.1 from April 2012. This provides a
more useful package than the previous version, complete with examples and
handling distfiles for the i386 and amd64 architectures. This was originally
in pkgsrc-wip and cleaned up for pkgsrc HEAD. Resolved PR/46914 Not a
complete ChangeLog since the version in pkgsrc, but here's what could be
scraped from HOMEPAGE:

The April 2012 version of Cg 3.1 added these improvements:

    Improved GLSL support for clip semantics
    Fixed a runtime bug concerning gp4 and gp5 geometry programs
    Various documentation updates

The February 2012 version of Cg 3.1 added these improvements:

    Added Cg language support for uniform buffers
    Added OpenGL Uni\ufb01ed Buffer Object (UBO) support for buffers
    Added OpenGL GLSL version 110 and 120 translation support
    New tessellation examples added
    New uniform buffer examples added
    VC10 projects added for examples

The February 2011 version of Cg 3.0 added these improvements:

    Improved DX11 tessellation support
    Resolved an issue with nearly identical user defined types
    Resolved an issue with default values from unreferenced uniform parameters
    Support setting matrices beyond 96 float constants in the vp30 profile
    Application supplied compilation options now override those set by \ 
cgGLSetOptimalOptions
    Improved support for 'const' variables in the GLSL profiles
    Added sampler state documentation