Refactor of ZmqSocket (#109)

Changed data type of address from char[1000] to string to reduce stack size of object.

Removed redundant calls to Close

Removed function exposing the socket descriptor

Using functions from network_utils instead of duplicates

Added tests

slsDetectorCalibration/moenchExecutables/moenchZmqProcess.cpp

@@ -245,7 +245,7 @@ int main(int argc, char *argv[]) {
 	  delete zmqsocket;
 	  return EXIT_FAILURE;
 	} else 
-	  printf("Zmq Client at %s\n", zmqsocket->GetZmqServerAddress());
+	  printf("Zmq Client at %s\n", zmqsocket->GetZmqServerAddress().c_str());
 	
 	// send socket
 	ZmqSocket* zmqsocket2 = 0;