(1) Launch the simple_subscriber:

  simple_subscriber -p 1:localhost:5555 -s 2:localhost:6666 -n 10000


(2) Launch the simple_publisher:

  simple_publisher -p 1:localhost:5555 -s 2:localhost:6666 -n 10000


The -n is optional, and will default to 10000.  Make sure to provide the same
-n value to both processes.  This is the number of messages that will be
sent by the publisher, and the number of messages expected by the subscriber.
