sys: 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

sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

sys: 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

Revert r102953

The bitfile padding was always unallocated on real-world FreeBSD systems and
depended on the assumption that (abs(sizeof(long) - sizeof(char*)) <= 32).

Differential Revision: https://reviews.freebsd.org/D2667
Reviewed by: eadler
Sponsored by: DARPA, AFRL

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

Make the char *n_name member of struct nlist 'const'.
This avoids errors or __DECONST() from places with higher WARNS levels.

Adjust a local cache variable in ipcs to const as well
to compile in the new world order.

Suggested by: jhb
Reviewed by: jhb, kib, brueffer (man)

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

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core

Pad after "char *n_name;" in the !_AOUT_INCLUDE_ case so that struct nlist
has some chance of having the same layout in all cases on machines with
sizeof(char *) != sizeof(long).

repo copy nlist.h to sys/nlist_aout.h, and strip out the userland
declarations from the shared-with-kernel side of it.

Breath deep and take __P out of the system include files.

# This appears to not break X11, but I'm having problems compiling the
# glide part of the server with or without this patch, so I can't tell
# for sure.

$Id$ -> $FreeBSD$

Move nlist related defines from link.h into nlist.h. Clean up
nlist.h.

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.

Add the linker set stab types: N_SETA N_SETT N_SETD N_SETB N_SETV

Document some of the fields used by the new shlib code.

Obtained from: NetBSD

BSD 4.4 Lite Include Sources