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)

The last big commit: let usr.sbin/ use WARNS=6 by default.

Reimplementation of world/kernel build options. For details, see:

http://lists.freebsd.org/pipermail/freebsd-current/2006-March/061725.html

The src.conf(5) manpage is to follow in a few days.

Brought to you by: imp, jhb, kris, phk, ru (all bugs are mine)

NOINET6 -> NO_INET6

Turn on the extended syntax, which TCP_wrappers has by default, as
distributed.

Drop MAINTAINER bits from here.

Don't clobber CFLAGS.

Submitted by: bde

Perform a major cleanup of the usr.sbin Makefiles.
These are not perfectly in agreement with each other style-wise, but they
are orders of orders of magnitude more consistent style-wise than before.

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

Set the default manual section for usr.sbin/ to 8.

Add IPv6 scoped address support.
It enables us to control link-local connections by interface like
this:

ALL : [fe80::%ed0]/10 : allow
ALL : [fe80::]/10 : deny

Missing tcp_wrapper IPv6 support seemed to be a bug, so commit it.

Now when tcp_wrapper is enabled by inetd -wW,
several accesses which should be permitted are refused only for IPv6,
if hostname is used to decide the host to be allowed.
IPv6 users will be just upset.

About security related concern.
-All extensions are wrapped by #ifdef INET6, so people can completely
disable the extension by recompile libwrap without INET6 option.
-Access via IPv6 is not enabled by default.
People need to enable IPv6 access by changing /etc/inetd.conf at first,
by adding tcp6 and/or tcp46 entries.
-The base of patches are from KAME package and are actually daily used
for more than a year in several Japanese IPv6 environments.
-Patches are reviewed by markm.

Approved by: jkh

Submitted by: Hajimu UMEMOTO <ume@mahoroba.org>
Reviewed by: markm
Obtained from: KAME project

$Id$ -> $FreeBSD$

Build tcp_wrappers' userland. I am not building tcpd, because in a day
or two, inetd will gain the necessary functionality. At that stage,
I'll make wrapping the default for sendmail and portmapper as well.