This test case starts pluto, and then uses addconn to insert a conn
into pluto.  Pluto is then terminated.
This is a functional test case that validates the whack communications
and the whole addconn and starterwhack libraries.

Since pluto needs port 500/4500 (and 500 is privileged), most tests start it
with another port (7500), bound to 127.0.0.1.


