Add tests for WebGL2 non-POT texture support.

[dvander]

This is the WebGL1 texture-npot test with some changes to check that the non-power-of-two texture size operations pass on WebGL2. Of course the original texture-npot tests will fail when run in a WebGL2 context, but I wasn't sure if there was a way to exclude just that test.

[kenrussell]

@toji could you please review this and provide guidance about how to exclude the old NPOT texture tests when running on WebGL 2.0? Thanks.

[toji]

Update date to 2014, please.

[toji]

To exclude a test from the 2.0 set, add a --max-version 1.9.9 to the 00_test_list.txt entry for the test. See https://github.com/KhronosGroup/WebGL/blob/master/sdk/tests/conformance/context/00_test_list.txt#L1 for an example.

Otherwise the test looks good. Please add the flag described about and address the comment about the date and I'll merge it.

[dvander]

Thanks, that worked! Updated copyright year & added exclusion.