Remove $FreeBSD$: one-line .c pattern

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

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

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.

No functional change intended.

Document getent(1)'s ability to enumerate netgroup members.

MFC after: 3 days

Add support for netgroup, based on patch in the PR but made consistent
with existing style.

PR: bin/132692

Teach getent(1) to look up a hostname and find IPv6 addresses.

PR: bin/161548
Submitted by: matthew

Print INIT_PROCESS and LOGIN_PROCESS entries as well.

Even though our implementation of utmpx never emits these types of
records, they are part of POSIX. Do print them when they show up in the
database files.

While there, also print the type number of unsupported records.

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Change how getent utmpx works.

- Always require active, log or lastlogin to be provided.
- Allow the user to provide custom filenames.

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.

The NetBSD Foundation has granted permission to remove clause 3 and 4
from their software.

Obtained from: NetBSD

Also print UNIX timestamps in getent utmpx output.

Also let getent(1) print values of ut_pid.

Allow getent(1) to display utmpx entries as well.

Because getutxent also matches the typical get*ent format of library
routines, I thought it would be a good idea to teach it how to read
utmpx databases. getent(1) just gives a raw dump, which is very useful
when debugging problems related to parsing/logging.

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

cleanup code: remove superfluous comma at end of enumeration
declaration, remove useless "break" after exit(3) call, and add a
missing va_end(3) call.

The port number must be network byte order.

o By popular demand import getent(1) utility: a program retrieves
and displays entries from the administrative database specified by
database, using the lookup order specified in nsswitch.conf(5).

PR: bin/79903, bin/88460, bin/96536
Submitted by: Julien Gabel, Dan Nelson, Daniel J. O'Connor
Obtained from: NetBSD
Discussed with: ume, soc-bushman
MFC after: 1 month