Add complex-glsl test

The test creates shaders that use the maximum number of uniforms.
An implementation can successfully compile/link or not but
it must not crash.
Refactor glsl-conformance-test runner so it uses setTimeout

This way it won't timeout the browser.
Fix variable packing tests

When computing the maximum uniforms forgot to divide by
number of rows per uniform so the maximum for mat2, mat3 and mat4
was vastly too big
Merge pull request #255 from greggman/fix-packing

Fix variable packing tests
Merge pull request #256 from greggman/add-timeout-to-glsl-tests

Refactor glsl-conformance-test runner so it uses setTimeout
Merge pull request #257 from greggman/complex-shaders

Add complex-glsl test
update title
Add long expression test
Merge pull request #258 from greggman/add-long-expression-test

Add long expression test
Add temp experssion test
Merge pull request #259 from greggman/temp-expressions

Add temp experssion test
fix log message
Add nested function test
Merge pull request #260 from greggman/add-nested-function-test

Add nested function test