Refactor pingpair_test to remove all serial io from within the irq handler, as necessitated by Arduino 1.0

tests/pingpair_test/printf.h

@@ -1,5 +1,5 @@
 /*
- Copyright (C) 2011 James Coliz, Jr. <maniacbug@ymail.com>
+ Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
  
  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
@@ -16,7 +16,7 @@
 #ifndef __PRINTF_H__
 #define __PRINTF_H__
 
-#include "WProgram.h"
+#ifdef ARDUINO
 
 int serial_putc( char c, FILE * ) 
 {
@@ -30,4 +30,8 @@ void printf_begin(void)
   fdevopen( &serial_putc, 0 );
 }
 
+#else
+#error This example is only for use on Arduino.
+#endif // ARDUINO
+
 #endif // __PRINTF_H__