Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

yp*: fix -fno-common build

This is mostly two problems spread out far and wide:
- ypldap_process should be declared properly
- debug is defined differently in many programs

For the latter, just extern it and define it everywhere that actually needs
it. This mostly works out nicely for ^/libexec/ypxfr, which can remove the
assignment at the beginning of main in favor of defining it properly.

-fno-common will become the default in GCC10/LLVM11.

MFC after: 3 days

spdx: initial adoption of licensing ID tags.

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.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133

Remove duplicated header files

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.

Include <rpc/rpc_com.h> for a _rpc_dtablesize() prototype.

Approved by: das (mentor)

Use __FBSDID over rcsid[]. Protect copyright[] where needed.

ANSIfy and remove some dead code.

Sponsored by: DARPA, NAI Labs

Apply the following mechanical transformations in preparation for
ansification and constification:

s{\s+__P\((\(.*?\))\)}{$1}g;
s{\(\s+}{\(}g;
s{\s+\)}{\)}g;
s{\s+,}{,}g;
s{(\s+)(for|if|switch|while)\(}{$1$2 \(}g;
s{return ([^\(].*?);}{return ($1);}g;
s{([\w\)])([!=+/\*-]?=)([\w\(+-])}{$1 $2 $3}g;
s{\s+$}{\n};g

Also add $FreeBSD$ where needed.

MFC after: 1 week

Don't call syslog() without a format string.

Remove unused include.

$Id$ -> $FreeBSD$

getopt(3) returns -1 not EOF.

Use err(3). Remove multiply defined Id string.

Import rpc.ypupdated.

This program still needs work but does compile and run. It also
needs a man page.