hammer2 - SPAN protocol work, router work

hammer2 - SPAN protocol work, router work

* Fix SPAN relay sort and sequencing bugs.

* Start reworking the APIs to accomodate routed messages.  Start by
  creating a hammer2_router structure and adjusting most of the msg
  functions to pass it instead of the iocom.

* Fix hammer2_state races by moving the state allocation to
  hammer2_msg_alloc() instead of hammer2_msg_write(). This gives
  code a chance to assign the state->any.* field without having to
  worry about the state getting ripped out from under us.