Purge more stray embedded $FreeBSD$ strings

These do not use __FBSDID but instead use bare char arrays.

Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41957

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.

Remove the 3rd clause ("advertising clause") of the BSD license as
permitted by the University of Berkeley on July 22, 1999.

Reviewed by: imp
MFC after: 1 week

More -Wmissing-variable-declarations fixes.

In addition to adding missing `static' keywords:
- bin/dd: Pull in `extern.h' to guarantee consistency with source file.
- libexec/rpc.rusersd: Move shared globals into an extern.h.
- libexec/talkd: Move `debug' and `hostname' into extern.h.
- usr.bin/cksum: Put counters in extern.h, as they are used by ckdist/mtree.
- usr.bin/m4: Move `end_result' into extern.h.
- usr.sbin/services_mkdb: Move shared globals into an extern.h.

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.

Port all apps in libexec/ from libulog to utmpx.

Make rpc.ruserd work with utmpx/libulog.

Because strings are now null-terminated, I've decided to just use an
array of utmpx structures, instead of the separated strings. This means
we just copy the entire utmpx structure and point to the strings within
the structures directly.

Perform cleanups to rpc.rusersd:

- Perform whitespace fixes. Use tabs instead of 8 spaces.
- Make it build at WARNS=6.

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

Include stdlib.h to get exit()'s prototype.

Spell void * as void * rather than caddr_t. This is complicated by the
fact that caddr_t is often misspelled as char *.

Sponsored by: DARPA, NAI Labs

o __P removal
o use new style prototypes and function definitions
o signal handlers need an argument. Mark it unused.

$Id$ -> $FreeBSD$

Make these programs compile and work correctly now that /usr/include/rpcsvc
has been ANSI-fied.

Pointed out by: bde

Remove unused #includes and make it compile again with -DDEBUG. Use syslog()
instead of errx() when being a daemon.

Use err(3). -Wall cleaning. cosmetics in man page.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Remove trailing whitespace.

Make two variables static so that the compiler warnings are
vanishing. As far as i know rpc.rusersd is single_threaded, so
this shouldn't be a problem.

__386BSD__ -> __FreeBSD__

I know that many of these entries are bogus and need to be revisited,
but let's get the tree working again for now and then do a pass through
looking at all the __FreeBSD__ entries, shall we?

rusersd from FreeBSD 1.1.5.1
Reviewed by: geoff.
Submitted by: John Brezak