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

Add the Clang specific -Wmissing-variable-declarations to WARNS=6.

This compiler flag enforces that that people either mark variables
static or use an external declarations for the variable, similar to how
-Wmissing-prototypes works for functions.

Due to the fact that Yacc/Lex generate code that cannot trivially be
changed to not warn because of this (lots of yy* variables), add a
NO_WMISSING_VARIABLE_DECLARATIONS that can be used to turn off this
specific compiler warning.

Announced on: toolchain@

Remove redundant WARNS?=6 overrides and inherit the WARNS setting from
the toplevel directory.

This does not change any WARNS level and survives a make universe.

Approved by: ed (co-mentor)

Fixed "make checkdpadd" (missing library dependencies).

Approved by: re (kensmith)

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

Style: NO_MAN doesn't need any value.

Start the dreaded NOFOO -> NO_FOO conversion.

OK'ed by: core

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

For variables that are only checked with defined(), don't provide
any fake value.

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.