sbin: 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 $FreeBSD$: alt two-line .c pattern

Remove /^\s*__RCSID\("\$FreeBSD\$"\);\n\n/

Remove $FreeBSD$: two-line .h pattern

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

sbin/routed: Remove unused code for sgi and NetBSD.

MFC after: 2 weeks

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.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

routed(8): use NULL instead of zero for pointers.

Spelling fixes for sbin/

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.

Add some consts, remove some unused stuff and other attempts to calm
FlexeLint down.

Modernize prototypes (ie: no extern)

Make lots of stuff static.

Kick WARNS level up to 6 by fixing various trivial warnings.

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

Remove #ident directives, they don't exist on the vendor branch anymore.

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core, imp

Virgin import of rhyolite.com routed v2.27

$Revision$ -> $FreeBSD$ (more cleanup needed here)

$Id$ -> $FreeBSD$

Latest-and-greatest routed.
Includes RIPv2 and Router Discovery.

Submitted by: Vernon Schryver <vjs@calcite.rhyolite.com>

Spelling, add rcsid, remove unused #includes.
Convert 1000000 usec to 1 sec 0 usec.
Use provided safe malloc (rtmalloc()) instead of malloc(): exit on allocation
failure.
Correct use of .Nm
Add usage() and use errx().

Virgin import of new BSD/SGI routed. This update contains a number
of important bug fixes.

Obtained from: Vernon J. Schryver <vjs@mica.denver.sgi.com>