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

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

Use socklen_t instead of int32_t where appropriate to pacify new GCC4
warnings.

Submitted by: kan
MFC after: 1 week

Update bthidd(8) code and hook it up to the build.
bthidd(8) now was integrated with vkbd(4) and supports
multiple keyboards via vkbd(4)/kbdmux(4).

The code was tested with Apple Bluetooth keyboard and
SE k700i cell phone (remote control feature).

MFC after: 1 month

Properly convert L2CAP PSM values in sockaddr_l2cap to LE16 byte order.

Noticed by: Iain Hibbert < plunky at rya-online dot net >
MFC after: 3 days

Fix problem with session termination. bthidd(8) maintains two L2CAP
connections to Bluetooth HID device. As soon as Bluetooth HID device
is powered off (or goes out of RF range) the stack will terminate both
connections. File descriptors for both connections will become active
on next select(2) call. Because bthidd(8) processes file descriptors
in order, it will detect descriptor for one of the closed connections
first and kill the session. However, there is still a second (active)
descriptor that used to point to the same session. bthidd(8) used to
assert() if it cant find session by file descriptor, which was wrong.

While I'm here fix a couple of typos in parser.y

Reported by: Eric Anderson anderson AT centtech DOT com
MFC after: 3 days

Check in updated bthidd(8). This is still work in progress.

Start committing Bluetooth HID (Human Interface Device) support.
Note: bthidd(8) is still not complete. Need to commit kernel
support (a-la Linux /dev/input) to feed HID events into kernel.
Also need to write bthidd(8) and bthidd.conf(5) man pages.