Unicode and the io, os, and lfs libraries on Windows

[Matt Campbell <mattcampbell@...>]

As I mentioned the other day, I've been developing a collection of Win32 
API bindings.  These bindings all use the Unicode versions of their 
corresponding Win32 functions; they take and return UTF-8 strings.  Now, 
the problem is that the io, os, and lfs libraries don't take or return 
UTF-8 strings on Windows; they use the system's default code page, which 
is never UTF-8 (how I wish it was!).  This means that if I do something 
like this:

appDataDir = shlobj.GetSpecialFolderPath(nil, shlobj.CSIDL_APPDATA)
f = io.open(appDataDir .. "\\foo.cfg")

the second statement won't work if the application data directory 
contains non-ASCII characters.

For consistency and to avoid debugging headaches on non-English Windows, 
I want to use UTF-8 everywhere.  How should I solve this problem?

Thanks,
Matt