Remove copyright strings ifdef'd out

We've ifdef'd out the copyright strings for some time now. Go ahead and
remove the ifdefs. Plus whatever other detritis was left over from other
recent removals. These copyright strings are present in the comments and
are largely from CSRG's attempt at adding their copyright to every
binary file (which modern interpretations of the license doesn't
require).

Sponsored by: Netflix

usr.bin: 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/

Mark usage function as __dead2 in programs where it does not return

In most cases, usage does not return, so mark them as __dead2. For the
cases where they do return, they have not been marked __dead2.

Reviewed by: imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/735

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

Remove the advertising clause from UCB copyrighted files in usr.bin. This
is in accordance with the information provided at
ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change

Also add $FreeBSD$ to a few files to keep svn happy.

Discussed with: imp, rwatson

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.

Static'ify signal handler which is not called from outside.

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

ANSIify function definitions.
Add some constness to avoid some warnings.
Remove use register keyword.
Deal with missing/unneeded extern/prototypes.
Some minor type changes/casts to avoid warnings.

Reviewed by: md5

Consistently use FBSDID

remove __P

Use STD{ERR,IN,OUT}_FILENO instead of their numeric values. The
definitions are more readable, and it's possible that they're
more portable to pathalogical platforms.

Submitted by: David Hill <david@phobia.ms>

Include missing header files which define functions for which gcc has
builtins (e.g., exit).

Submitted by: Mike Barcroft <mike@q9media.com>

Remove home-grown prototypes of time() and localtime().

Reviewed by: md5(1)

Call usage() if given more than 1 argument.

Submitted by: "Andrew R. Reiter" <arr@watson.org>
Obtained from: OpenBSD

$Id$ -> $FreeBSD$

Don't let secs variable wrap if <= 2.

PR: 6290
Submitted by: Ruslan Ermilov <ru@ucb.crimea.ua>

1. Don't reject 0145 if started at 22XX.
Applied suggested fix from Andrew Andrew <andrew@ugh.net.au> with
some stylistic changes. Thanks.
2. #include <sys/time.h> -> #include <time.h>
3. Removed #include <sys/param.h>
4. Use setlocale(3) and strftime(3) instead of ctime(3).
5. Clean up -Wall warnings.
6. Make sure, time to leave are integral minutes if the argument
is absolute. (i. e. without "+"). If started at 10:10:55 with
argument "1020" it computed time to leave as 10:20:55 instead of
10:20:00.

PR: 5395

Check fgets' return value, silent -Wall.
Obtained from: OpenBSD

BSD 4.4 Lite Usr.bin Sources