For now only for simple replacements, so there is not a big difference
from what we had before.

Signed-off-by: Nadav Goldin <[email protected]>

It appears that on older libvirt versions(such as 1.3 on Ubuntu16.04),
/dev/urandom backend model is not supported. I could not trace in libvirt's
changelog when that was changed, and I hope this is not a different
issue specific to Ubuntu16.04.  However, we know for sure that /dev/urandom
works on libvirt version greater than 2002001. So here we add a simple
condition on that.

Signed-off-by: Nadav Goldin <[email protected]>

1. Ensure network scripts are working(on older cirros other
interfaces were just not configured properly).

2. Use same domain template as el6 with the normal serial console.

Signed-off-by: Nadav Goldin <[email protected]>