Promote WEBGL_security_sensitive_resources from proposal to draft.
Merge pull request #406 from mvujovic/promote-security-sensitive-resources-to-draft

Promote WEBGL_security_sensitive_resources from proposal to draft
add antialias coverage for conformance/context/premultiplyalpha-test.html.
Promote WEBGL_draw_buffers to 'Community Approved'.
Merge pull request #409 from jdashg/draw-buffers

Promote WEBGL_draw_buffers to 'Community Approved'.
Remove duplicated glEnumToString functionality in webgl-test-utils
Remove unused webglTestLog function
Remove duplicate of glErrorShouldBe and always use one in wtu
Remove duplicate of shouldGenerateGLError and always use one in wtu

In addition, shouldGenerateGLError now reuses glErrorShouldBe. Error
message format changes a bit, but contains the same information.
Get rid of unused webgl-test.js entirely
Merge pull request #407 from JunJiang/add-antialiasing-case

add antialias coverage for conformance/context/premultiplyalpha-test.html
Merge pull request #410 from NVIDIA/utility-cleanup

Utility cleanup
Merge branch 'master' into texture-size-limit-fix2