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
Merge pull request #310 from NVIDIA/fix-uniform-limits

Account for literal constants taking up uniform storage