Remove $FreeBSD$: one-line .c comment pattern

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

Remove support for IPsec algorithms deprecated in r348205 and r360202.

Examples of depecrated algorithms in manual pages and sample configs
are updated where relevant. I removed the one example of combining
ESP and AH (vs using a cipher and auth in ESP) as RFC 8221 says this
combination is NOT RECOMMENDED.

Specifically, this removes support for the following ciphers:
- des-cbc
- 3des-cbc
- blowfish-cbc
- cast128-cbc
- des-deriv
- des-32iv
- camellia-cbc

This also removes support for the following authentication algorithms:
- hmac-md5
- keyed-md5
- keyed-sha1
- hmac-ripemd160

Reviewed by: cem, gnn (older verisons)
Relnotes: yes
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D24342

General further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

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.

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

Cleanup of userland __P use

Commit IPv6 support for FAST_IPSEC to the tree.
This commit includes all remaining changes for the time being including
user space updates.

Submitted by: bz
Approved by: re

synchronize with latest kame tree.

behavior change: policy syntax was changed. you may need to update your
setkey(8) configuration files.

libipsec and IPsec related apps. (and some KAME related man pages)

Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project