adds a new uci firewall - iptbales and netfilter packages need to be rewrapped...

adds a new uci firewall - iptbales and netfilter packages need to be rewrapped when we switch to this firewall as default - there are some examples in the file /etc/config/firewall - iptables-save/restore are still missing - hotplug takes care of adding/removing netdevs during runtime - misisng features ? wishes ? let me know ...

SVN-Revision: 12089