move most offload functionality from NIC to TOE
factor out all socket and inpcb direct access
factor out access to locking in incpb, pcbinfo, and sockbuf
- add support for T3C
- add DDP support (zero-copy receive)
- fix TOE transmit of large requests
- fix shutdown so that sockets don't remain in CLOSING state indefinitely
- register listeners when an interface is brought up after tom is loaded
- fix setting of multicast filter
- enable link at device attach
- exit tick handler if shutdown is in progress
- add helper for logging TCB
- add sysctls for dumping transmit queues
- note that TOE wxill not be MFC'd until after 7.0 has been finalized
MFC after: 3 days
