Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

White space cleanups to bring closer to RELENG_7

- update firmware to 5.0
- 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

Update the buffer management support code needed by the tcp offload module

When building cxgb as a module make include paths relative to the driver's root.
This will make it possible to build the module out of tree against an older src tree.

MFC after: 3 days

(MFp4)
- upgrade to reflect state of 1.0.0.86
- move from firmware rev 3.2 to 4.0.0
- import driver bits for offload functionality
- remove binary distribution clause from top level files as it
runs counter to the intent of purely supporting the hardware

MFC after: 3 days