RDIO-scanner streams integration

[Clark985]

RDIO-Scanner has the ability to have other instances push audio to it using the API Keys/Downstreams config.

It would be slick if SDRTrunk could directly add a downstream RDIO instance, similar to how Broadcastify Calls streams are added.

I run multiple remote SDRTrunk+RDIO-Scanner instances that all feed to a main RDIO-Scanner instance. This would eliminate the need for RDIO-scanner (using dirwatch) to exist on each remote instance.

[Clark985]

It looks like someone is coding this module per #1476 - can probably close this discussion.

I'll gladly beta test when it's ready.