Merge "Update doxygen" into tizen

diff --cc include/widget_app.h
index 6b4d1d9,8413c33..f387349
--- 1/include/widget_app.h
--- 2/include/widget_app.h
+++ b/include/widget_app.h
@@@ -314,10 -314,10 +314,10 @@@ int widget_app_add_event_handler(app_ev
   * @return #WIDGET_ERROR_NONE on success,
   *         otherwise an error code (see WIDGET_ERROR_XXX) on failure
   * @retval #WIDGET_ERROR_NONE Successful
-  * @retval #WIDGET_ERROR_INVALID_PARAMETER Invalid parameter
   * @retval #WIDGET_ERROR_NOT_SUPPORTED Not supported
+  * @retval #WIDGET_ERROR_INVALID_PARAMETER Invalid parameter
   * @retval #WIDGET_ERROR_FAULT Unrecoverable error
 - * @see watch_app_add_event_handler()
 + * @see widget_app_add_event_handler()
   */
  int widget_app_remove_event_handler(app_event_handler_h event_handler);