Add message payload, and output total msgs sent at shutdown.
Make sure we're copying from the input buffer
Start the ChainRouter when we create it, don't make the client do it.
Gotta use the new message API.
Don't need to pass the RecycleChan in, it's already available through the
PipelineConfig.
Centralize decoder management w/ mappings from Header_MessageEncoding
to specific decoders.
first pass at getting MGI to work w/ hand-off pipeline design