Per working group discussion, added section on enforcing packing restrictions for uniforms and varyings, and referenced it from documentation for shaderSource, compileShader, and linkProgram.
Merge pull request #134 from kenrussell/packing

Per working group discussion, added section on enforcing packing restric...
added a conformance test for mipmap generation on rendered textures
Merge pull request #135 from pyalot/master

Conformance test for mipmap generation on rendered textures
Update mipmap-fbo test to use common testing functions
Merge pull request #136 from greggman/update-mip-fbo-test

Update mipmap-fbo test to use common testing functions