a new trick to add to winetricks

[Troy Wolbrink]

I've found the winetricks script invaluable in trying to get my app
running on Wine.  But I found that when installing msxml6, I needed to
change the overrides for msi.dll and msiexec.exe to "builtin,native".  I
previously installed the native msi20, and msxml6 wouldn't install with
the native installer.  It installs fine with the builtin installer.

Thanks,
Troy