[Piglit] ARB_texture_cube_map_array : initial tests

[Dave Airlie]

This is a bunch of tests to start testing ARB_texture_cube_map_array.

The first patch modifies textureSize, the rest are standalone tests,
and the final patch just adds to all.tests. All tests pass on the
nvidia binary 295.59.

I think the one area I've left to write a test for is GetTexImage,
otherwise I think I've covered quite a lot of the spec.

Regards,
Dave.