When a machine is heavily loaded, it can severely delay the time it
takes for the OS to start a process once it's asked to do so. Our
5 second timeout that we were giving the test process to connect
to the test harness seemed like plenty of time, were it not for the
fact that the test process itself was not being started in time when
CPU throttling was in effect.

This change updates the test timeout to begin counting only once the
test process has been started. We keep the original timeout in play
in the event that the test process *never* starts up for some reason,
but we up that timeout value to 5 minutes.