Update Docker images o that additional command line arguments to the docker run command are passed to the shairport-sync application.
(This is the behaviour of the original 3.3.8 docker image but was missing from the AirPlay 2 development version.)
Use the s6-overlay system on the Classic docker image.
Fix a bug that delayed metadata appearing in the D-Bus, MPRIS and MQTT interfaces.
Clean up the generation of Play/Pause/Stop conditions.
Add Pause stage generation for AirPlay Buffered streams.
CLean up some of the documents.
The shairport-sync instance runs as user and group shairport-sync which has reduced privileges.
The "classic" docker image now uses the s6-overlay to manage processes.
Mike Brady
Charles