run-tests: attempt to fix iolock handling Ideally, when using -j and -i together, when a prompt comes up, we'd like all other output to wait (but testing to continue!). This gets other output to wait by adding back a bunch of the locking that formerly existed. We switch to a recursive lock to deal with the restructuring due to unittest compatibility. Running tests continue to run, but now the scheduler doesn't schedule any new tasks while waiting at a prompt because no task slots become available due to result output happening in the thread and blocking on the iolock.