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/

renice: Avoid segfault if -n flag is given without argument.

Fixes: 65ee0a8495538
MFC after: 1 week
Sponsored by: Klara, Inc.
Reviewed by: kevans
Differential Revision: https://reviews.freebsd.org/D39623

renice: fix argument order.

The target modifiers (-g, -p, -u) may occur in any position except
between -n and its argument; furthermore, we support both the old
absolute form (without -n) and the modern relative form (with -n).

Sponsored by: Klara, Inc.

renice: support -- as per POSIX.

Sponsored by: Klara, Inc.
MFC after: 1 week

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.

ANSIfy various tools in usr.bin/.

Most of these tools properly build at WARNS=6, except for their K&R
function declarations. Fix this, so we can bump WARNS as well.

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

Sync program's usage() with manpage's SYNOPSIS.

The usage string: renice [priority | [-n incr]] ... assumed that the part
`priority | [-n incr]' was optionnal which is wrong according to the code.
Add FreeBSD Id.
Reviewed by: maxim

Sync usage message with manual page synopsis.

Bad numeric arguments or usernames should cause non-zero exit status.

Process and user ID arguments must be treated as decimal integers,
not octal or hex. This is the way it was before revision 1.10.

PR: 36950
Submitted by: Peter Avalos <pavalos@theshell.com>

Accept decimal user IDs with -u option as well as usernames.

PR: 36950

Diagnostic messages belong on stderr, not stdout. SUSv3 specifies that
renice may not use stdout at all.

o Fix an arguments number check in -n case.
o Remove duplicated prio check, donice() makes it for us.

Spotted by: David Schultz <dschultz@uclink.Berkeley.EDU>
MFC after: 1 week

Implement POSIX -n option, cleanup an arguments parsing a bit.

PR: bin/34076, bin/35929
Reviewed by: bde
Obtained from: NetBSD
MFC after: 1 week

style(9) cleanup.

Reviewed by: bde
MFC after: 1 week

remove __P

Warns cleanups.

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

#include <errno.h> where needed. Kill extern int errno;.

Minor warnings in tip corrected.

$Id$ -> $FreeBSD$

Use err(3). Add usage() and prototypes.

Remove trailing whitespace.

BSD 4.4 Lite Usr.bin Sources