A basic liveliness test of DDS.

run_test.pl
  Runs a test of liveliness. This test has 2
  participants, and checks liveliness for both local
  and remote assocations. This is the inforepo version.

run_test.pl take
  Run the same test but "take" instead of "read".

run_test.pl rtps_disc
  Runs the same test but using rtps_udp transport and
  rtps discovery.
