[Libguestfs] [PATCH 0/5] v2v: Handle disks with snapshots (RHBZ#1172425).

The first commit removes the --dcpath parameter, which just makes the following stuff simpler. Since libvirt has supported getting datacenterpath from VMware since Oct 2015, it's time to drop this hairy parameter. The rest is quite a complicated series of refactorings, followed by a very simple change to add handling of snapshots taken from old virt-v2v. Rich.