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/

spdx: initial adoption of licensing ID tags.

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.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133

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 unused includes. Make it WARNS=6 friendly. Concerning bin/2442, make
a new function dup_shell() to replace ok_shell() and make it unconditionnally
strdup() its result to make the caller's code simplier. Change ok_shell() to
just return an integer value suitable for tests (it was used mainly for that
purpose). Do not use strdup() in the caller's code but rely on dup_shell()
that will do the job for us.

PR: bin/2442

Do not compare unsigned int values with ULONG_MAX. The comparison is
always false on 64bit platforms and GCC 3.3.1 issues warning there.

Use libutil and libypclnt for all passwd manipulation and NIS needs.

Sponsored by: DARPA, NAI Labs

Minor post warns stuff.
1) Fix up vendor IDs for files I'm touching and put FBSDID in the right place.
2) Cast return value of snprintf to size_t rather than casting sizeof() to
an int, 'cos we know snprintf returns a non-genative number.
3) Avoid 'char *blank = "";' by just strduping. This could be bad sometimes,
but all these variables usually point at malloced memory so this makes
them always point at malloced memory.

Fix warns, ANSIfy, use __FBSDID(), sort headers.

Tweaks to allow compiling -Wall (mostly adding "const" to char rcsid[]).

Print some warnings if root invokes chpass and sets the
shell to one of the following:

- a non-existent file
- a non-regular file
- a file without any execute bits set

The shell is still set to whatever they entered even if the above
conditions exist (hey, it is the super user doing this after all :-),
but this might give the admin. some warning that they are about to screw
themselves and give them a chance to fix it before it is too late.

Inspired by: some new FreeBSD user on USENET who set his root shell
to a shell that doesn't exist and now can't gain access to root (don't
worry, I sent him some mail on how to recover from this).

Remove trailing whitespace.

BSD 4.4 Lite Usr.bin Sources