run-tests: move t test parsing into its own function Test parsing is somewhat complicated. This patch extracts it into its own function. The impetus of this patch is folding tsttest() into the TTest class. Subsequent patches will continue this work until tsttest() no longer exists.

run-tests: roll pytest() into PythonTest._run() Python was the old runner function. It no longer needs to exist since the PythonTest class took its job.