ap-mdns: initial structure
ap-mdns: add configuration templates for printer services and avahi daemon
ap-mdns: write avahi configuration dynamically
ap-mdns: fix avahi config writing
ap-mdns: fix interface logging
ap-mdns: filter out all mDNS traffic in tap interfaces
ap-mdns: handle handle all cached event correctly
ap-mdns: fix iptables interface flag according to to the chain
ap-mdns: fix typo
ap-mdns: restart avahi each time a new network is configured
ap-mdns: do not try to add interfaces dynamically

Avahi does not support it without full hard restart.
ap-mdns: setup event listener before handling cached events

Previously it was possible that some events got lost after having
handled all cached events but before we had an event listener up and
running.
ap: maintain a list of current networks

This list can be used by other components suchs as ap-dnsproxy or
ap-mdns. Currently they are maintaing their own versions.

Move also the network setup to library scripts to ensure that the
network is added/removed before script parts are being run.
ap-mdns: use the network list mantained by ap
ap-dnsproxy: use the network list maintained by ap
ap-dnsproxy: use port 53533 instead of 5353 which is standard mDNS port
ap-mdns: simplfy the default avahi daemon conf
ap-mdns: simplify iptables management
ap-mdns: refactor iptables management
ap-dnsproxy: simplify iptables management