qubes_prepare_saved_domain.sh now takes optional second argument, the
filename. The content of the file will be copied (via xenstore) to DVM
and executed just before save. This makes it possible to preload memory
with useful apps.
qubes_setup_dnat_to_ns script sets up DNAT rules for DNS traffic; it is
triggered by dhclient or NetworkManager, and manually (in case there is
a static resolv.conf).
Put IP-dependent rules in qubes-core, after local ip is known. It could be
further improved by introducing custom chains, to enable iptables save.
Restrict FORWARD.