add new public API: jack_port_rename

This is semantically similar to jack_port_set_name() but because it is also passed a jack_client_t*, it can
contact the server to ensure that not only the rename is done but that port rename callbacks are delivered
appropriately

jack.h

@@ -763,8 +763,20 @@ int  jack_port_untie (jack_port_t *port) JACK_OPTIONAL_WEAK_DEPRECATED_EXPORT;
  *
  * @return 0 on success, otherwise a non-zero error code.
  */
-int jack_port_set_name (jack_port_t *port, const char *port_name) JACK_OPTIONAL_WEAK_EXPORT;
+int jack_port_set_name (jack_port_t *port, const char *port_name) JACK_OPTIONAL_WEAK_DEPRECATED_EXPORT;
 
+/**
+ * Modify a port's short name.  May NOT be called from a callback handling a server event.  
+ * If the resulting full name (including the @a "client_name:" prefix) is
+ * longer than jack_port_name_size(), it will be truncated.
+ *
+ * @return 0 on success, otherwise a non-zero error code.
+ *
+ * This differs from jack_port_set_name() by triggering PortRename notifications to 
+ * clients that have registered a port rename handler.
+ */
+int jack_port_rename (jack_client_t* client, jack_port_t *port, const char *port_name) JACK_OPTIONAL_WEAK_EXPORT;
+	
 /**
  * Set @a alias as an alias for @a port.  May be called at any time.
  * If the alias is longer than jack_port_name_size(), it will be truncated.