Add function to automatically run all tests within a given suite only

[abaire]

Make it so hitting "X" (or whatever) on a test suite in the menu runs just that suite automatically.

Running the entire set of tests takes a very long time now that we're also capturing z-buffers and reading via AGP access so it'd be useful to be able to run just a subset of the tests.

[abairmj]

starting work on this