Handle server down

[Desrever Nu]

Subscriber will hang there if there is no Streamer up.

handle with a timeout \

16:25:43.969 [main] INFO  com.nubits.nubot.nufeed.Subscriber - Connecting to server

[Desrever Nu]

Also see #746 .

Trying to make a connectionMonitor that calls a static boolean isStreamerUp()

not trivial

http://stackoverflow.com/questions/15184841/how-to-check-if-jzmq-socket-is-connected or https://github.com/zeromq/jeromq/issues/61

[Desrever Nu]

Passing this will skip waiting

byte[] reply = requestFirstSocket.recv(ZMQ.DONTWAIT);