Bison 3 fixes.

--- src/signature.y.orig	Sat Nov  7 16:02:12 2015
+++ src/signature.y	Sat Nov  7 16:02:41 2015
@@ -56,7 +56,7 @@ static void yyprint (/*FILE *p_file, int p_type, YYSTY
 
 %}
 
-%pure_parser 
+%define api.pure
 
 /* CONVENTIONS:  Reserved words are in ALL CAPS (plus markerSym)
 		Characters appearing in the grammar are reserved: