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

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

Build usr.bin/ with WARNS=6 by default.

Also add some missing $FreeBSD$ to keep svn happy.

Add the -H, -h and -P flags to vmstat. -P causes per-cpu output of
user/system/idle stats. -h feeds the memory column through
humanize_number() to reduce the amount of column overflowing. -H turns
this off. -h is turned on by default if stdout is a tty.

Teach vmstat -m and vmstat -z to use libmemstat(3). Certain
statistics from -z are now a bit different due to changes in the
way statistics are now measured. Reproduce with some amount of
accuracy the slightly obscure layouts adopted by the two kernel
sysctls. In the future, we might want to normalize them.

GC dosysctl(), which is now no longer used.

MFC after: 1 week

Put libdevstat before libkvm, because the former depends on the latter.

Finish the transition from libkvm to sysctl that I started a while ago.
The use of libkvm for post-mortem analysis is still supported (though it
could use more testing). We can now remove vmstat's setgid bit.

While I'm here, hack the interrupt listing code to not display interrupts
that haven't occurred unless the -a option was given on the command line,
and document this change.

Remove NO_WERRORs and WARNS=n's. To be revisited after GCC3.

WARNS=2 fixes, but set NO_WERROR, as there are some HardToFix(tm)
warnings originating in system headers.

Removed -I${.CURDIR}/.../sys from CFLAGS.

MAN[1-9] -> MAN.

Update system to new device statistics code.

Submitted by: "Kenneth D. Merry" <ken@plutotech.com>

Fixed DPADD.

More absolute paths

More merry makefile munging for man page compatability.

This commit was generated by cvs2svn to compensate for changes in r1590,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite Usr.bin Sources