Huh, richer UDP implementation...no warnings from GHC, and unit tests do pass...although not the UDP send/receive test.

Amusingly, all that work to abstract out Connections may not be appropriate. We'll see.
Removed obsolete listeners member from transports; renamed receiveMessage -> reciveSocketMessage in N.T.S; disabled UDP unit tests, as they are not ready.
Okay, code is a bit of a disaster and needs some cleanup, *but* UDP transport now does pass basic send / receive unit test.