Update libvpx snapshot to v0.9.7-p1 (Cayuga).

source/libvpx/vp8/common/mv.h

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 
 #ifndef __INC_MV_H
 #define __INC_MV_H
+#include "vpx/vpx_integer.h"
 
 typedef struct
 {
     short row;
     short col;
 } MV;
 
+typedef union
+{
+    uint32_t  as_int;
+    MV        as_mv;
+} int_mv;        /* facilitates faster equality tests and copies */
+
 #endif