Shutting down stack isn't properly implemented

[jonbo372]

you cannot shutdown the stack cleanly. Parts of the flow isn't implemented and other parts isn't properly implemented.

1. ListeningPoint::down - all of them are returning null, when they should be returning CompletionStage. And there is in fact no code to actually shut down the listening point.
2. NettyNetworkInterface::down - looks correct but as it turns out, there is also a CountdownLatch passed in which the calling code assumes is going to be called. Should really wait for the futures to complete. Either or, currently it isn't working. Either get rid of the latch or actually call countdown on it.
3. NettyNetworkLayer::stop - this is where it all starts and also the one that assumes the latch will be used, which it isn't. So latch.await will hang indefinitely.