Account for literal constants taking up uniform storage

According to GLSL ES spec 10.0.17 Appendix A section 7:

"When calculating the number of uniform variables used, any literal
constants present in the shader source after preprocessing are included
when calculating the storage requirements. Multiple instances of
identical constants should count multiple times."
Better explanation of literal constants taking up space
Don't use premultiplied alpha in most GLSL generator tests

Many GLSL function conformance tests can generate superluminal color
values, where red, green or blue > alpha. Since browsers don't do
clamping for these color values before they are unpremultiplied and
encoded as PNG when toDataURL is called, the on-screen display of these
tests did not reflect the actual numeric values generated by the shader.
This complicated debugging failed tests. Fix this by switching to a
context with a non-premultiplied drawing buffer in these tests.

This issue does not affect the programmatic comparison of test results,
since that is being done using readPixels.
Revert change to the frozen 1.0.1 suite

It makes sense to fix displaying superluminal values in 1.0.2, since lots
of implementations are still working on conformance, but with 1.0.1 it's
better to avoid this kind of changes.
Merge pull request #312 from NVIDIA/fix-superluminal-display

Don't use premultiplied alpha in most GLSL generator tests
Merge pull request #310 from NVIDIA/fix-uniform-limits

Account for literal constants taking up uniform storage