Import bmake-20121010
Relevant items from ChangeLog:
          o [Makefile.in:] protect syntax that only bmake parses correctly.
          o compat.c: ignore empty commands - same as jobs mode.
          o make.1: document meta chars that cause use of shell

Approved by:	marcelm (mentor)
Tag bmake/20121010

Approved by:	marcel (mentor)
Enable back the clang warning in if_ath.c.
Fix bug in r242852 that prevented CPU from becoming idle if kernel built
without SMP support.
Fix kassert that's not really valid for %CPU accounting.  The problem
here is race between decaying the resource usage in containers, and updating
per-process usage; basically, the former may cause per-container usage
to get smaller than per-process usage.

Submitted by:	Rudo Tomori
Finish removing obsolete man pages (add them to ObsoleteFiles.inc)

Submitted by:	many
Approved by:	cperciva
MFC after:	3 days
Follow the behavior as specified in POSIX:

if (exists AND (NOT f_option) AND
	((not_writable AND input_is_terminal) OR i_option))
		prompt

in particular, add the test for input_is_terminal

PR:		bin/173039
Submitted by:	Mark Johnston <markjdb@gmail.com>
Approved by:	cperciva
MFC after:	3 days
Some software, notably dialog(1), can understand back-tab, which is
typically bound to Shift-Tab. syscons produces ^]]Z for Shift-Tab, like
many VT100-like terminal (emulators). The plain xterm does not produce
this sequence, but ^I for both Tab and Shift-Tab.

PR:		conf/162787
PR:		bin/151229
Submitted by:	Stefan Bethke <stb@lassitu.de>
Submitted by:	Bruce Cran <bruce@cran.org.uk>
Approved by:	cperciva
MFC after:	3 days
Add a missing check for fread

Approved by:	cperciva
MFC after:	3 days
Make definition match declaration

Approved by:	cperciva
MFC after:	3 days
Check the range of the gid

Approved by:	cperciva
MFC after:	1 week
Fix error code if file isn't readable.

Approved by:	cperciva
MFC after:	1 week
Add deviceid to the disk output on boot to help debugging.

PR:		kern/173290
Submitted by:	Steven Hartland <steven.hartland@multiplay.co.uk>
Approved by:	cperciva
MFC after:	1 week
Add option to suppress just the plot in ministat while still retaining
the relative comparison (i.e., useful part).

Approved by:	cperciva
MFC after:	3 days
Only pass ip[46].addr when _addrl contains a value

Submitted by:	crees
Reviewed by:	Mike Jakubik <mike.jakubik@intertainservices.com>
Approved by:	cperciva
MFC after:	2 weeks
Avoid possible null deref if ypclnt_new returns null

PR:		bin/172979
Submitted by:	Erik Cederstrand <erik@cederstrand.dk>
Approved by:	cperciva
MFC after:	3 days
Fix memory leak in umount.c

PR:		bin/172553
Submitted by:	Erik Cederstrand <erik@cederstrand.dk>
Approved by:	cperciva
MFC after:	3 days
Be declarative about if an error has occured.

Fixes overflow on very large group files with lots of errors. This is
unlikely to occur in practice.

Approved by:	cperciva
MFC after:	1 week
Add support for a -q flag.  While here make the custom argument parsing
use getopt instead of hacking on it more.  This change also fixes the
method of silencing the compiler warning about gfn being used
uninitialized.

Approved by:	cperciva
MFC after:	1 week
This wasn't supposed to be in there - I committed the wrong patch.

Approved by: cperciva (implicit)