lpr: Remove now unused fallback definition for __FBSDID

Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D41956

Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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.

Change the closeallfds() routine to use closefrom() when it is
available (closefrom() was added to FreeBSD in 8.0-release).
The selection is made at compile-time, as I still compile a
FreeBSD-based version of lpr&friends on other platforms.

While testing I out that (at least on my system) lpd has been
closing 11095 fd's, when there are only 6 fd's open. The old
code took 120 times more clocktime than calling closefrom().
(although that was still less than 2/1000-ths of a second!)

Reviewed by: jilles
MFC after: 2 weeks

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.

Introduce a new lp.cdefs.h file, which will be used to make it
somewhat easier to build this lpr on other operating systems.
This simply includes <sys/cdefs.h> when that is appropriate,
and then checks for any cdefs-ish macros that lpr uses, and
defines them if they don't already exist. This is only a start
at making freebsd's lpr less of a hassle to port. It is mainly
added so all of lpr can be changed to use the __FBSDID() macro,
without making it *more* of a hassle to build on other OS's.

Reviewed by: discussed with bde and obrien
MFC after: 15 days