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

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

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

Approved by: re (implicit)

Revert most part of 200420 as requested, as more review and polish is
needed.

Remove unneeded header includes from usr.bin/ except contributed code.

Tested with: make universe

Support shadow.byname and shadow.byuid maps, protecting them by
insisting on privileged port access.

Include /var/yp/Makefile.local if it exists and suggest using
it to override /var/yp/Makefile behaviour.

Approved by: re (kib)
MFC after: 3 weeks

Sync program's usage() with manpage's SYNOPSIS.

Stop gcc warnings

Apply the following mechanical transformations in preparation for
ansification and constification:

s{\s+__P\((\(.*?\))\)}{$1}g;
s{\(\s+}{\(}g;
s{\s+\)}{\)}g;
s{\s+,}{,}g;
s{(\s+)(for|if|switch|while)\(}{$1$2 \(}g;
s{return ([^\(].*?);}{return ($1);}g;
s{([\w\)])([!=+/\*-]?=)([\w\(+-])}{$1 $2 $3}g;
s{\s+$}{\n};g

Also add $FreeBSD$ where needed.

MFC after: 1 week

WARNS=2 fixes
__FBSDID() additions
some include file sorting.
Some Makefile sorting.

WARNS?=2 is not added to the Makefile, because it is going to be
default for usr.bin/
NO_WERROR is set because there are rpc*.h file issues.

Include missing header files which define functions for which gcc has
builtins (e.g., exit, strcmp).

$Id$ -> $FreeBSD$

Use err(3). Add references to others man pages. Wait for the user to
supply the domain before computing a default one.
Obtained from: OpenBSD

Add an alias for master.passwd -> master.passwd.byname to the list
of convenience map aliases.

Move more YP user programs over.