Use the explicit 'W' (wide) symbols from the Windows API to provide
Unicode support regardless of whether UNICODE is defined:
- SetFileAttributesW
- LPCWSTR
Define UNICODE anyway for the sake of thirdparty code that uses the
aliases, which only work properly when UNICODE is defined:
- SetFileAttributes
- LPCTSTR
If UNICODE is not defined then the aliases refer to the narrow symbols:
- SetFileAttributesA
- LPCSTR
But the explict 'W' symbols are still available. The aliases are only
needed for compatibility with code written prior to Windows NT.
