- glLight*/glMaterial and their queries
- Use new packed enums in these entry points, except for lightmodel
which stays GLenum to be consistent with other generic glGet's
- State.cpp: New glGet* queries related to light model and
light/normal rescale enablement
- GLES1State.cpp: Functions to get/set lighting/material state
- Validation for lighting/materials

+ Add a few convenience methods to random_utils for sampling
non-negative floats and a sampler for random booleans

BUG=angleproject:2306

Change-Id: If7ba0c0a0dc75f88fbaa986b904f1ea96ee6512e
Reviewed-on: https://chromium-review.googlesource.com/1065502
Commit-Queue: Lingfeng Yang <lfy@google.com>
Reviewed-by: Geoff Lang <geofflang@chromium.org>