Refactor how properties are parsed

src/curve_server.hpp

@@ -107,7 +107,9 @@ namespace zmq
 
         void send_zap_request (const uint8_t *key);
         int receive_and_process_zap_reply ();
-        int parse_property_list (const uint8_t *ptr, size_t length);
+
+        virtual int property (const std::string name,
+                              const void *value, size_t length);
     };
 
 }