Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

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

Get in some basic infrastructure for Bluetooth SCO support.

MFC after: 3 months

Several changes breaking netgraph module ABI collected together:
- reorder structures fields (XX_refs) a bit to group fields modified
same time together. According to my tests it gives up to 10%
SMP performance benefit on real workload due to reduced inter-CPU
cache trashing.
- change q_flags from long to int as long is not really needed there and
it's usage with atomics is argued by some people.
- move NGF_WORKQ flag into the separate field q_flags2 as it protected by
queue mutex instead of node writer protection used by the rest of flags.
- move nd_work queue entry to ng_queue structure to which it is more
related and make it STAILQ instead of TAILQ as now it is a classic FIFO.
- remove q_node pointer from ng_queue structure as it is not really needed.
- reimplement item queue using STAILQ instead of own equal implementation.
As soon as BT subsystem has own item queues using ng_item.el_next update
it also.
- change depth field in ng_item from uintptr_t to u_int. It was made
uintptr_t to keep ABI compatibility.

Reviewed by: julian, emax
Tested with: Netperf cluster

/* -> /*- for license, minor formatting changes

Change double include protection style in headers to match
the rest of Netgraph code.

Reviewed by: imp, ru
Approved by: imp (mentor)

Part one of undating the bluetooth code to the newest version

Submitted by: Maksim Yevmenkin <m_evmenkin@yahoo.com>
Approved by: re@

The second try a committing the bluetooth code
Has been seen to work on several cards and communicating with
several mobile phones to use them as modems etc.

We are still talking with 3com to try get them to allow us to include
the firmware for their pccard in the driver but the driver is here..
In the mean time
it can be downloaded from the 3com website and loaded using the utility
bt3cfw(8) (supplied) (instructions in the man page)

Not yet linked to the build

Submitted by: Maksim Yevmenkin <myevmenk@exodus.net>
Approved by: re