[libvirt] [PATCHv9 0/4] persistent device modification for qemu

Updated against the latest git tree, no major changes since a week ago. Thank you for reviews in previous ones. Purpose of patches: Now, virsh at(de)tach-device/disk/...etc.. doesn't support to update inactive domain's definition even with the --persistent flag. To update persistent modification of inactive domains, we have to use virsh edit. So, if we want to update inactive domain definition with scripts, we need to use other command/libs than libvirt. I'd like to use libvirt/virsh in scripts. This patches adds to support for updating domain definition via virsh with scripts. This series just includes 'disk' updates but I'll add more. Thanks, -Kame