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

src/trusted/validator_ragel/unreviewed/compare_dfa.py

-#!/usr/bin/python
+#!/usr/bin/env python
 # Copyright (c) 2013 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.
 
 import sys
 import os
 sys.path.append(os.path.join(os.path.dirname(__file__), '..'))
 import dfa_parser
 
 
@@ skipping 45 matching lines @@
   _, start_state1 = dfa_parser.ParseXml(filename1)
   _, start_state2 = dfa_parser.ParseXml(filename2)
 
   Traverse(start_state1, start_state2, [])
 
   print 'automata are equivalent'
 
 
 if __name__ == '__main__':
   main()