lib: 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 $FreeBSD$: one-line .c pattern

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

Use __SCCSID() for SCCS IDs.

- Define NO__SCCSID in CFLAGS to preserve existing behavior of omitting
SCCS IDs by default.
- While here, fix the $FreeBSD$ in pw_util.c to use __FBSDID.

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

libutil: Use O_CLOEXEC for internal file descriptors from open().

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.

Remove California Regent's clause 3, per letter

ANSIfy, WARNSify, CONSTify. Bit of style(9)-ify.

Tidy up. Sort headers.

Add __FBSDID()s to libutil

Correct uu_lock_txfr. I don't think this ever worked correctly.

$Id$ -> $FreeBSD$

Get the pid right if a stale lock file exists.
PR: 10531
Submitted by: Lawrence D. Lopez <lopez@cisco.com>

Cast pid_t to int for sprintf.
Pointed out by: Charlie Sorsby <crs@hgo.net>

Add uu_lock_txfr() to transfer ownership of a successful
uu_lock() to another process.

Implement canonical locking protocol
Suggested by: joerg

Improve weak locking by using flock()

Make uu_* const correct.

Suggested by: joerg

Add Id
Reduce space for error bufer from 512 to 128: there is no such long strings
can be returned from strerror()

Code space optimization in uu_lockerr()

Remove unused USE_PERROR define and syslog.h include
Use snprintf instead of sprintf to avoid buffer overflows
Use snprintf in uu_lockerr instead of lots of hardcoded constants
and not null-terminated strncpy
Return "" for OK and "device in use" for INUSE, it allows simple
strcpy(buf, uu_lockerr(retcode)) without testing for special OK
case (NULL was there) and obtaining meaningful result for INUSE
("" was there) without special testing for it too.

Remove the syslog stuff, and allow various return values
in uu_lock(). Add uu_lockerr() for turning the results of
uu_lock into something printable. Remove bogus section in man page
about race conditions allowing both processes to get the lock.
Include libutil.h and use uu_lock() correctly where it should.

Suggested by: ache@freebsd.org

Move uucplock into libutil and create a manual page.