firewall: Improve ubus support

* Use network.interface dump call instead of individual status calls
  to reduce overall netifd lookups and invokes to 1 per fw3 process.

* Allow protocol handlers to assign a firewall zone for an interface
  in the data section to allow for dynamic firewall zone assignment.

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38504 3c298f89-4303-0410-b956-a3cf2f4a3e73
odhcp6c: filter similar RAs spammed by some ISPs

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38505 3c298f89-4303-0410-b956-a3cf2f4a3e73