MFC r261296:

Merge from CheriBSD:
commit c1acf022c533c5ae27e0cd556977eafe3f5959eb
Author: Brooks Davis <brooks@one-eyed-alien.net>
Date:   Fri Jan 17 21:46:44 2014 +0000

	Add an option WITHOUT_NCURSESW to suppress building and linking to
	libncursesw.  While wide character support it useful we'd like to
	only need one ncurses library on embedded systems.

Sponsored by:	DARPA, AFRL
MFC r261300:

Add a missing options file.

Sponsored by:	DARPA, AFRL
MFC: 261298
Merge from CheriBSD:
commit 70b8f0c127db6b80411789d237b403cc64a93573
Author: Brooks Davis <brooks@one-eyed-alien.net>
Date:   Mon Jan 27 22:53:57 2014 +0000

	Move mtree.5 to usr.sbin/nmtree.
	Remove note that mtree 2.0 format files aren't supported.

Sponsored by:	DARPA, AFRL
MFC: r260889, r260890, r260911:

	r260911 | imp | 2014-01-20 10:45:36 -0700 (Mon, 20 Jan 2014) | 5 lines

	Don't lock in the generic grab just to lock again in the specific grabs.

	r260890 | imp | 2014-01-19 12:39:13 -0700 (Sun, 19 Jan 2014) | 11 lines

	Introduce grab and ungrab upcalls. When the kernel desires to grab the
	console, it calls the grab functions. These functions should turn off
	the RX interrupts, and any others that interfere. This makes mountroot
	prompt work again. If there's more generalized need other than
	prompting, many of these routines should be expanded to do those new
	things.

	Reviewed by:    bde (with reservations)
MFC r261299:

Merge from CheriBSD:
commit 2d581e8caf79d7a0f5a24590eccd06da90cccb74
Author: Brooks Davis <brooks@one-eyed-alien.net>
Date:   Mon Jan 27 22:57:51 2014 +0000

	Add WITHOUT_FMTREE to disable building fmtree.

Sponsored by:	DARPA, AFRL