With the permission of Romain Degez, CTO of Smartjog.

Signed-off-by: Sébastien Luttringer <sebastien.luttringer@smartjog.com>

Libvirtd version 0.8.8 is capable of handling connections to virtio consoles but
the Python API is broken.

Uses a fork and permits to set ionice on child.

/!\ Don't use logging for logging as it would (maybe) end in a deadlock for the
child.

Needed for disk synchronisation during live migration.

Harmless renaming.

Initialization, re-authentication...