* It's not particularly scalable and can be brittle to driver changes, and we
can use targeted specific pixel tests to check what we really want - to see if
the output has rendered correctly.
* Overlay tests still check files directly - this is a future refactor to
remove.
* This is better than testing by platform/platform version, because we can check
specifically for extensions and avoid running a test we know will fail because
extensions aren't supported.
* Built entirely independently of the main renderdoc build (for now).
* Contains python scripts & framework for running tests on a renderdoc build,
which will be run nightly.
baldurk