Include Arduino.h (for pre-compiled header speedup)

Wire.cpp

@@ -19,6 +19,8 @@
   Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts
 */
 
+#include <Arduino.h>
+
 #if defined(__AVR__)
 
 #include "Wire.h"

Wire.h

@@ -28,7 +28,7 @@
 #elif defined(__AVR__)
 
 #include <inttypes.h>
-#include "Arduino.h"
+#include <Arduino.h>
 
 #define BUFFER_LENGTH 32
 #define WIRE_HAS_END 1