Update old-style definitions to ANSI, remove a couple of register
definitions along the way. Fixed gcc 4.1 build (thank you vax)

branches: 1.14.6;
Declare strsignal(3) in <string.h>, per POSIX-2008, and adjust
documentation accordingly.

Fixes PR standards/41325 from Perry E. Metzger.

WARNS=4

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22280, verified by myself.

Delint.
Remove trailing ; from uses of __weak_alias(). The macro inserts this if
needed.

delint

Make these compile without __AUDIT__.

const poisoning.

These two don't belong in string.h, but unistd.h

If port provides __weak_alias(), provide an Standard C and POSIX pure
identifier namespace by renaming non standard functions and variables
such that they have a leading underscore. The library will use those
names internally. Weak aliases are used to provide the original names
to the API.

This is only the first part of this change. It is most of the functions
which are implemented in C for all NetBSD ports. Subsequent changes are
to add the same support to the remaining C files, to assembly files, and
to the automagically generated assembly source used for system calls.
When all of the above is done, ports with weak alias support should add
a definition for __weak_alias to <sys/cdefs.h>.

Fix RCSID's
Use "extern.h" where appropriate.

- convert unsafe strcpy(), strcat() and sprintf() to the `n' versions.
- some KNF.

Change size of array passed to __strsignal() from 128 to NL_TEXTMAX.

__strerror() and __strsignal() have been broken out into their own files
and use message catalogs if NLS is defined.
Increased the size of char buffers used by strerror() and strsignal();
the error and signal strings may be much longer in some locales.

branches: 1.1.2;
Add strsignal() function like on Solaris.
We might want to be able to retrieve a locale-specific signal description
(from a message catalog) and we need a function call API for that feature.