sys: 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

sys: Remove $FreeBSD$: one-line .c pattern

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

Sync strlcpy with userland version, again

No functional change.

Please remember to update libkern copies of libc functions when you update
libc.

Sponsored by: Dell EMC Isilon

Sync strlcpy with userland version.

MFC after: 1 month

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

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

MFlibc: Remove extra closing parenthesis.

/* -> /*- for copyright notices, minor format tweaks as necessary

Use sys/libkern.h not /usr/include/string.h

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