AU: Class to perform delta updates.

A class to perform delta updates and the associated unittests. Also,
change the delta diff generator executable to be able to apply a
delta, which is handy for debugging.

TEST=Attached unit test, hand-tested on real build images
BUG=552

Review URL: http://codereview.chromium.org/1718001
diff --git a/omaha_hash_calculator.h b/omaha_hash_calculator.h
index c96f75e..900da80 100644
--- a/omaha_hash_calculator.h
+++ b/omaha_hash_calculator.h
@@ -5,10 +5,10 @@
 #ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_HASH_CALCULATOR_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_HASH_CALCULATOR_H__
 
-#include "base/basictypes.h"
 #include <string>
 #include <vector>
 #include <openssl/sha.h>
+#include "base/basictypes.h"
 
 // Omaha uses base64 encoded SHA-1 as the hash. This class provides a simple
 // wrapper around OpenSSL providing such a formatted hash of data passed in.