Container packaging

[almereyda]

It is very convenient to use the shairport-sync daemon in a container.

Using nqptp alongside can be preferable for such setups.

This would require container packaging for the nqptp daemon.

[mikebrady]

Thanks for this idea. As you may know, NQPTP runs inside the same container that Shairport Sync is running in. This is because the interface from NQPTP to Shairport Sync is through a Shared Memory interface and a UDP port -- port 9000, and I don't know how well that would all work between separate Docker images (?)