CafeGLSL v0.1.1

Fixes in this release:

• Using gl_FragCoord will no longer rely on a Mesa-internal uniform variable
• Loops work correctly now. Previously loops would only work if the compiler was able to unroll them completely
• Uniform per-block size limit raised to 64KB (4096 * vec4) for all stages
• discard statement in fragment shader is now working

Special thanks for their contributions: @GaryOderNichts @Crementif