- mark the 'geoip-use-ecs' option obsolete; warn when it is used
  in named.conf
- prohibit 'ecs' ACL tags in named.conf; note that this is a fatal error
  since simply ignoring the tags could make ACLs behave unpredictably
- re-simplify the radix and iptable code
- clean up dns_acl_match(), dns_aclelement_match(), dns_acl_allowed()
  and dns_geoip_match() so they no longer take ecs options
- remove the ECS-specific unit and system test cases
- remove references to ECS from the ARM