- Move audio configuration into a service module to make it easily
usable by multiple hosts.
- Allow configuration of AirPlay 2 name.
- Don't set MQTT topic of Shairport-Sync (AirPlay 2) explictly. Defaults
to hostname now.
- Don't set sound.enable anymore, since its not needed.
- use nqptp
- use Shairport Sync and nqptp versions, which work
- disable IPv6, since Shairport Sync doesn't work with it for some
reason
- configure firewall for AirPlay 2
- use correct subnet