Lots of small things, see ChangeLog
diff --git a/Include/traceback.h b/Include/traceback.h
index f86306d..a1b6d5e 100644
--- a/Include/traceback.h
+++ b/Include/traceback.h
@@ -30,6 +30,8 @@
 
 /* Traceback interface */
 
+struct _frame;
+
 int tb_here PROTO((struct _frame *));
 object *tb_fetch PROTO((void));
 int tb_store PROTO((object *));