fix or drop zipOpen2/unzOpen2

[berolinux]

zipOpen2 and unzOpen2 currently cast a zlib_filefunc_def* to mz_stream_vtbl*
Since those structs contain different functions with different parameters in a different order, this will crash the calling application at best and corrupt data (unzOpen2 actually calling into a function that opens the file for writing) at worst.

The functions should either be implemented in a compatible way, or at least removed so users don't think this is going to work before actually running into something that calls the functions.

[nmoinvaz]

I have implemented the ioapi support. Only thing missing is wide-character ioapi support for Windows. If somebody really cares about that they can figure it out themselves.

[gvollant]

my very old code was

#ifdef IOWIN32_USING_WINRT_API
#ifdef UNICODE
    if ((filename!=NULL) && (dwDesiredAccess != 0))
        hFile = CreateFile2((LPCTSTR)filename, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
#else
    if ((filename!=NULL) && (dwDesiredAccess != 0))
    {
        WCHAR filenameW[FILENAME_MAX + 0x200 + 1];
        MultiByteToWideChar(CP_ACP,0,(const char*)filename,-1,filenameW,FILENAME_MAX + 0x200);
        hFile = CreateFile2(filenameW, dwDesiredAccess, dwShareMode, dwCreationDisposition, NULL);
    }
#endif
#else
    if ((filename!=NULL) && (dwDesiredAccess != 0))
        hFile = CreateFile((LPCTSTR)filename, dwDesiredAccess, dwShareMode, NULL, dwCreationDisposition, dwFlagsAndAttributes, NULL);
#endif

If I remember, that was for WINRT which was not compatible with Ansi API....