[project @ 2003-08-19 16:39:13 by simonmar]
Use the wide-char classifications from the C library if available.
This gives us Unicode-aware isLower, isUpper, isAlpha etc.
On Unix, you have to set your locale to something. This is usually
done by setting the environment variable LANG, eg.
export LANG=en
This stuff *should* also work on Windows, except that Windows uses a
16-bit wchar_t so will get it wrong for characters > '\xffff'. However,
I figured it was better to use the system-supplied functionality
rather than trying to implement this stuff ourselves.