bugzilla #862085: automatically filter disks with imsm or ddf superblocks, v3

I'm not quite sure how to actually get the patch I sent to this list applied, so I thought I'd go ahead and create an entry in the Redhat/Fedora Bugzilla system. It's bug #862085, the URL is https://bugzilla.redhat.com/show_bug.cgi?id=862085 .

I don't know if the Product (fedora) / Version (rawhide) / platform (unspecified, linux) etc settings are correct. Please adjust if you think it is needed.

Mike.