This fixes a bug where Process events were being delivered to secondary
listeners when the Private state thread listener was processing the
event. That meant the secondary listener could get an event before the
Primary listener did. That in turn meant the state when the secondary
listener got the event wasn't right yet. Plus it meant that the
secondary listener saw more events than the primary (not all events get
forwarded from the private to the public Process listener.)
This bug became much more evident when we had a stop hook that did some
work, since that delays the Primary listener event delivery. So I also
added a stop-hook to the test, and put a little delay in as well.
44d9692e6a