Added WebSocketMessageQueue

ixwebsocket/IXWebSocket.h

@@ -114,7 +114,10 @@ namespace ix
         WebSocketSendInfo ping(const std::string& text);
         void close();
 
+        // Set callback to receive websocket messages.
+        // Be aware: your callback will be executed from websocket's internal thread!
         void setOnMessageCallback(const OnMessageCallback& callback);
+
         static void setTrafficTrackerCallback(const OnTrafficTrackerCallback& callback);
         static void resetTrafficTrackerCallback();