hammer2 - spanning tree and messaging work
* Fix numerous bugs and cleanup the messaging infrastructure further.
Fix issues with state tracking and incorrect message flags, assert that
flags are correct.
* Fix issues with connection termination. All active transactions must be
completely closed from both ends before the iocom can be destroyed.
Fix bugs in the MSGF_DELETE message simulator when a socket error occurs
(simulating the other end closing any active transactions going over
the iocom).
* Implement the spanning tree relay code. The relay code is even relatively
optimal though ultimately we need to add additional filters to make
client<->service rendezvous's less cpu intensive.