[PATCH setup] Add new option '--compact-os'

[Christian Franke]

Achim Gratz wrote:
> ...
> Deciding the compression and compression type by the extension is prone
> to miss a lot of real-world things, though, so you'd hope that that was
> recognized by the compact OS code itself instead of working around it?

Yes. The compression only succeeds if the number of clusters could be 
reduced. Otherwise it fails with ERROR_COMPRESSION_NOT_BENEFICIAL and 
leaves the file as is.

Regards,
Christian