Modify test runner to dump translated shaders

This change adds a test runner feature that dumps translated shaders
while running glsl conformance tests.

For each test, a summary json file is created which has all the
information like original shaders, test description, whether shader
should compile and path to translated shaders.

For all the glsl test shaders that compile successfully, translated
shaders are dumped to separate files so that it can be fed directly
to the compiler.

All the translated shader and summary files are compressed into a
tar.gz at the time of finishing tests.

New test runner command line option --dump_shaders is added and it
needs to be passed for dumping translated shaders.
Merge pull request #4 from NVIDIA/apatole-dev

Modify test runner to dump translated shaders
Rename 'finishTest' to 'finishIndividualTest'

This change renames 'finishTest' to 'finishIndividualTest' to avoid
any confusion with already existing 'finish' handler. And also
added comment describing finishIndividualTest.
Merge pull request #5 from NVIDIA/apatole-dev

Rename 'finishTest' to 'finishIndividualTest'
Merge pull request #726 from NVIDIA/master

Modify test runner to dump translated shaders
Add shader link validation test for variant/invariant varying mismatch.
Clean up some of the setTimeout() in the tests.

Some should be replaced with waitForComposite,
some should be replaced with requestAnimFrame,
some should use the timeout 0 instead of a positive value.
Add comments pointing to the spec.
Merge pull request #730 from zhenyao/varying

Add shader link validation test for variant/invariant varying mismatch.
Use wtu.checkCanvasRect when we can.
Merge pull request #731 from zhenyao/timeout

Clean up some of the setTimeout() in the tests.
Merge pull request #732 from zhenyao/clean

Use wtu.checkCanvasRect when we can.