usr.bin: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

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.

Synchronize m4(1) with OpenBSD

Synchronize with laster version of m4 from OpenBSD and NetBSD
This bring better compatibility with gnum4

Reviewed by: cognet
Approved by: cognet
Obtained from: OpenBSD, NetBSD

Remove the advertising clause from UCB copyrighted files in usr.bin. This
is in accordance with the information provided at
ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change

Also add $FreeBSD$ to a few files to keep svn happy.

Discussed with: imp, rwatson

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.

Remove redundant declarations of getopt(3) externals (since <unistd.h> does
take care of them), and add __FreeBSD__ to the defined() checks for the
_PATH_DIVNAME.

Bring OpenBSD m4(1) off of the OPENBSD vendor branch, and add the -s option,
$FreeBSD$ identifiers, and fix initialisation to stderr to happen in a function
as stderr is not the same in CURRENT as in OpenBSD.

Reviewed by: obrien

Create temporary files in a secure directory, instead of using multiple
filenames based on a single invocation of mktemp() in /tmp, which is
easily predictable after the first one.

Audited by: markm

Import OpenBSD m4 as of today.

BSD 4.4 Lite Usr.bin Sources