fix/BROOKLYN-36

fix saveIptablesRules
To save the iptables rules, will installing `iptables-persistent` really do that? I thought that would just restore the iptables on restart based on the contents of either `/etc/iptables/rules.v4` or `/etc/iptables/rules.v6`. Would we not also need to do `dpkg-reconfigure iptables-persistent` or `iptables-save >/etc/iptables/rules.v4`?

But empirical evidence (and ideally live tests!) trumps everything else.

See http://unix.stackexchange.com/questions/125833/why-isnt-the-iptables-persistent-service-saving-my-changes