[Libguestfs] [PATCH NOT TO BE APPLIED] builder: make-template: Add --encrypted

I was attempting one way to solve: https://bugzilla.redhat.com/show_bug.cgi?id=1400332 "RFE: virt-builder should support templates with encrypted filesystems" However this approach doesn't really work because templates containing encrypted partitions cannot be compressed, and therefore the guest template would be a multi-gigabyte download. I better approach will likely be to use the new qcow2 encryption (LUKS-based) recently written by Dan Berrange. I am posting this patch just to record the code changes. Rich.