Allow user to override Wifi regulatory domain set in Atheros EEPROM.

Globally enable OpenWRT config option CONFIG_ATH_USER_REGD for ar71xx
builds.
Avoid DNS reverse lookups when listing to-be-deleted iptables rules

These lookups can take quite some time when there are many
user-defined rules (such as a set of rules derived from a block
list).  We never look at the domain names anyway, so it's safe to have
just the IP addresses dumped.
Merge branch 'dev-iptables-list-n'