- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Renumber clauses to reduce diffs to other versions

NetBSD, OpenBSD, and Android's Bionic number the clauses 1 through 3,
so follow suit to make comparison easier.

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

Approved by: imp

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Replace wcsstr() with an implementation based on strstr(), which is far
more efficient. The problem with the previous implementation was that it
calculated the length of the first argument ("big") with wcslen() when
it was not necessary.

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.