closely synch the sender/consumer startup.

Support -N name option to uniquely identify the trafgen on a machine
trafgen uses the name to further qualify event selection.

Support -l logname option to turn on TG's per-packet logging.  There is
no NS interface to this right now.  You would have to turn this on manually
by restarting the trafgens and then restarting the event-sched to replay
events.

Turn on some debugging printfs for now til things have stablized a bit.
The trafficconfig function in libsetup.pm currently redirect stdout/stderr
to a file in /tmp.