Windows clib functions cannot handle non-ASCII Unicode file paths

If a user stores SWORD-related files under a path including non-ASCII characters in Windows, the library will be unable to access them.

The library currently uses the standard C library calls to methods such as open, mkdir, fopen, etc. On most modern systems these calls are able to handle Unicode paths fine but on Windows these are limited to ASCII(or possibly current 8-bit system encoding?)-only.

We should update the library to use wrapper functions around the required functionality for building on Windows. Xiphos is using a patched version of the library that uses compatible calls to GLib functions. I am attaching their patch for reference.