Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

usr.sbin: normalize paths using SRCTOP-relative paths or :H when possible

This simplifies make logic/output

MFC after: 1 month
Sponsored by: Dell EMC Isilon

Convert usr.sbin to LIBADD
Reduce overlinking

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

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

Several cleanups to ipfwpcap(8).

- Enable WARNS?=6.
- Include missing headers.
- Mark prog and pidfile as static. Remove unneeded initializer.
- Use ANSI prototypes.
- Remove unneeded fp variable.
- snprintf() guarantees the buffer to be null terminated. Remove
unneeded - 1 and bzero call.
- Remove unneeded casting.

Submitted by: Pawel Worach, Christoph Mallon

- Import the HEAD csup code which is the basis for the cvsmode work.

Add manual page for ipfwpcap(8).

Reviewed by: phk, brueffer
Submitted by: Niclas Zeising <lothrandil@n00b.apagnu.se>

Add a small tool which captures packets on a DIVERT socket and writes
them as pcap (tcpdump) format data to a file or pipe.

Volunters wanted for: manpage
Contributed by: P Kern <pkern@cns.utoronto.ca>