Make sure config.h or the copy of that gets included only once to reduce duplicate include

warnings.

test/testisocd.c

@@ -1,6 +1,5 @@
-/* $Id: testisocd.c,v 1.6 2008/03/22 18:08:25 karl Exp $
-
-  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Rocky Bernstein 
+/* 
+  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2011 Rocky Bernstein 
   <rocky@gnu.org>
   
   This program is free software: you can redistribute it and/or modify
@@ -21,6 +20,7 @@
 
 #ifdef HAVE_CONFIG_H
 # include "config.h"
+# define __CDIO_CONFIG_H__ 1
 #endif
 
 #include "portable.h"