It have nothing to do with xenstore, so change the name to not mislead.
Also get rid of unused "xid" parameter - we should use XID as little as
possible, because it is not a simple task to keep it current.
Move DispVM creation to qfile-daemon-dvm/QubesDisposableVm from
qubes-restore. As actual restore is handled by libvirt, we don't get
much from separate qubes-restore process.
This code still needs some improvements, especially on performance.
Opening a DispVM when the TemplateVM is running forces savefile
regeneration. Checking real root.img modification time (taking into
account root-cow.img) is tricky, so display a warning instead.
