[VB6] 7-zip support

[wqweto]

@ wqweto

Yes. Since your project deals primarily with adding support for the 7-Zip format for VB6, I thought, why not include Unicode-aware file handling as well? I've just tested the 7-Zip File Manager and it can deal with Unicode filenames pretty well. But of course, it's up to you if you want to implement it or not. Consider my 'request' as a suggestion only.

Unicode filename handling is implemented in latest version 1.0.2 -- mostly `CreateFile` and `Get/SetFileAttributes` are checking for unicode FS support.

It turns out zip file format has an extension for unicode filenames that 7-zip supports through `-mcu` parameter. I just also updated the sample showing how to set this parameter for creating unicode zips.

cheers,
</wqw>