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.