Clients that will be at the ClientProtoInfo protocol level (or above)
will now receive an asynchronous INFO protocol when the server
they connect to adds a *new* route. This means that when the cluster
adds a new server, all clients in the cluster should now be notified
of this new addition.
Ensure that all socket writes are protected with deadlines.
For connection Close(), also use deadlines since in case of TLS,
the Close() will send an alert (do a write) if the handshake was
completed. If the peer is not reading, this would cause the Close()
to hang.
* There was a race during unsubscribe()
* 'go test -race' reports a race in TestSetLogger test. This one could be ignored since we normally invoke SetLogger only on server startup. That being said, Travis failed when I tried to submit a PR for the fix of the unsubscribe race. So proposing to fix the logger too.
race condition:
- a client is closed at the same time as an incoming SUB message occurs.
- the subscription is added to the srv.sl even though the socket is
closed.
- the connection cleanup has already run, so the bad state is never
corrected
- now messages may be forwarded to a client without a connection
- messages will not be forwarded to a router that needs it now, because
processMsg assumes the router already received it
