usr.bin: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

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/

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.

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

display.c:
- 'savech' is only used if it is set a few lines above where
it is used, initialize it to silence warning.

- 'length' is either -1 or greater than 0, hence it is safe to cast it
to unsigned when comparing it here.

odsyntax.c:
- 'p' is assigned either (*argvp)[0] or (*argvp)[1] which both are
char *. 'num' and 'end' are assigned values based on 'p'.
Hence use char * instead of unsigned char * for these variables.

'&end' as the second argument to strtoll does not need to be casted
to char** any more.

This solves a
'dereferencing type-punned pointer will break strict-aliasing rules'
warning when compiling with -O2.

parse.c:
- 'prec' is only used when sokay == USEPREC and sokay = USEPREC
when 'prec' is assigned. Hence 'prec' is not used uninitialized,
initialize it to silence warning.

- The code involving 'nextpr' is hard to follow, but I belive
'nextpr' will not be used unless it is initialized.
Anyway, IF 'nextpr' is used uninitialized it is better to
get a consistant error (seg fault, when dereferencing a NULL pointer)
than potentially accessing some random memory.

The above changes makes hexdump WARNS=6 clean even when compiled with
-O2. Hence bump WARNS to keep it clean.

Tested by: CFLAGS='-O2 -pipe' make universe

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

Make the output tidier when multiple integer formats are requested by
attempting to line up values into columns.

Obtained from: NetBSD (idea)

Overhaul hexdump's od syntax code to handle the -s -A -j -N -t options that
SUSv3 requires and give od a proper manual page.

PR: 36783

Declare variables that were extern'd in multiple places in hexdump.h.

PR: 36783

Un-deprecate od(1): rename the `deprecated' variable to `odmode', remove the
deprecation warning from the utility and manual page. Since this utility
is required by POSIX, it's not likely to be removed any time soon.

This is leading up to the addition of the P1003.1-2001 -s -A -j -N -t options.

PR: 36783

remove __P

File positions are off_t nowdays, not long, so:
strtol -> strtoll
fseek -> fseeko

NOTE: that fseek not works for >long offsets files per POSIX:

[EOVERFLOW] For fseek( ), the resulting file offset would be a value which
cannot be represented correctly in an object of type long.

$Id$ -> $FreeBSD$

Clean up some ambiguous nested if/elses.

Localize it

Use err(3) instead of local redefinition, incorporate `hd' in usage str.

compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.

Merge from Lite2

Import some parts of CSRG 4.4BSD-Lite2 usr.bin sources to fix tree build.

Remove trailing whitespace.

BSD 4.4 Lite Usr.bin Sources