Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

- ANSIfy function definitions
- use nul when we are looking for a terminating character where appropriate

Approved by: imp

Simplify by removing useless local variables and explicit null termination.

Remove unnecessary #include <assert.h>; it was used to bring in the
_DIAGASSERT macro on NetBSD, but we don't need it.

Add restrict qualifiers where C99 permits them. All of these already had
restrict qualifiers on their prototypes in <wchar.h>.

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

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.

Unbreak world; _DIAGASSERT macro is not available in FreeBSD.

initial import of locale insensitive wcs* and wmem* functions.

Obtained from: NetBSD and Citrus.