libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Keep those.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D42385

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Make strlcpy/strlcat slightly easier to read.

Bring small upstream updates.

Obtained from: OpenBSD

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.

Add restrict qualifiers to the parameters to strlcpy() and strlcat().
The annotation mainly just serves as a hint that they're not intended
for use with overlapping strings.

- License change to a less restrictive one;
- ANSIfy;
- Convert do {} while loop -> while {} for clarity;
- Sync RCS ID with OpenBSD;

Obtained from: OpenBSD

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

o Make grep ^strlcpy work: put a return value type on separate line.

Remove extra closing parenthesis added in revision 1.4.

Noticed by: Andrea Campi

Back out the `hiding' of strlcpy and strlcat. Several people
vocally objected to this safety belt.

`Hide' strlcpy and strlcat (using the namespace.h / __weak_reference
technique) so that we don't wind up calling into an application's
version if the application defines them.

Inspired by: qpopper's interfering and buggy version of strlcpy

Remove 'register' keyword.

rcsid[]->__FBSDID

Make the rcsid and FreeBSD IDs more sane in the wcs* and wmem* files.
Do the same for the non-wcs*/wmem* files while I'm here.

Use the latest version of these files from OpenBSD.

1) Safty change from casper dik was added to OpenBSD's sources since I
grabbed them. milltert@openbsd.org
2) Split up strlcpy to improve efficiency of the common case.
milltert@openbsd.org
3) Cleanup of cross references for man page. {alex,aaron}@openbsd.org

Pointed out by: deraadt@openbsd.org

Import strl{cat,cpy} from OpenBSD.

Obtained from: OpenBSD