io.Copy() blocking indefinitly when chaining tunnels

[rgzr]

Investigating here the issue explained in #12 by @stankovic-marko

With your changes related to how the connections are closed, the tests TestReconnectTunnel and TestReconnectRemoteTunnel are not passing. A connection is stalled because it doesn't detect the other side closing the connection.

Could you provide a more detailed example of what's happening when you are chaining the tunnels? What connection are you closing and what are the results? We should find another solution that don't break current behavior.