Revisit implementation of TUNNEL and shared transport

TUNNEL and shared transport are not supported at the moment (2.10.Alpha5). The main complexity behind TUNNEL and shared transport is that we have to change StubReceiver model. StubReceiver reads messages of the socket on the TUNNEL side. With shared transport turned on StubReceiver would have to be changed because we are receiving byte arrays for all channels sharing transport. We need some special StubReceiver multiplexer so to speak which will read messages and then pass off the byte arrays to other Receivers which will in turn pass them as messages to appropriate channel above transport. Each byte array passed around have to be pre appended with some identifier....and so on.