Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r242372:
atrun(8): scale default load average limit with the number of CPUs

Previously atrun refused to run jobs if load average was not below fixed limit of 1.5.

PR: 173175
Approved by: trasz (mentor)

MFC r240974: atrun: Do not assume that MAXLOGNAME <= 100.

The reserved space for fmt was exactly sufficient for a two-digit value of
MAXLOGNAME - 1.

PR: bin/171815
Submitted by: Jeremy Huddleston Sequoia

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Don't use UT_NAMESIZE here to determine the maximum username length.

Add PAM support to atrun(8).

Actually use new features of perr() and perrx().

Make perr() variadic and add perrx() to use in cases where
errno is irrelevant. Some code duplication can be reduced
if perr() is variadic and perrx() is available.

Use a single setusercontext(3) instead of a bunch of basic syscalls.
Besides aesthetic benefits, that makes at(1) jobs subject to such
login.conf(5) settings as resource limits.

Spotted another copy of the loony error message.

Fix an error message that was beside the point.

Fix a typical off-by-one error that can result in an unterminated string:

strncpy(dst, src, sizeof(dst));

by substituting the safer strlcpy() for strncpy().

X-Security: none (the source string isn't user-supplied)

Don't be sexist - fix a typo.

Fix a few cases that relied on 'implicit int' (constraint violation in C99).

o Eliminate __P
o Use new-style function definitions
o remove some !__STDC__ code
o eliminate register

by by -> by

Obtained from: OpenBSD
MFC After: 1 week

Don't hard-code a buffer size

$Id$ -> $FreeBSD$

Fixed printf format errors.

Cosmetic in error strings. Sort Xrefs. Add usage (with syslog capability).

Do setlogin() before changing uid/gid, since
`at/batch' requires this.

Obtained from: me && OpenBSD

Submitted by: Philippe Charnier <charnier@xp11.frmug.org>
Fixes name size limitation (was hardcoded to 8).
Closes PR#3258

compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Check for expired passwords before allowing access to the system.

Upgrade to 2.9

Remove trailing whitespace.

Add some useful sendmail options

Upgrade.
Close security holes reported.

Added the Linux atrun command as hacked by Chris Demetriou for NetBSD.