hammer2 - spanning tree and messaging work

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.