**/*.py: use /usr/bin/env to find python

src/trusted/validator_ragel/check_decoder.py

-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 Generate all acceptable sequences from acyclic DFA, run objdump and
 decoder on them and compare results.
 """
 
 import itertools
@@ skipping 259 matching lines @@
   total = 0
   for prefix, count in results:
     print prefix
     total += count
 
   print total, 'instructions were processed'
 
 
 if __name__ == '__main__':
   main()