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

src/trusted/validator_ragel/verify_validators_dfa.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.
 """%prog [option...] xmlfile
 
 Simple checker for the validator's DFA."""
 
 from __future__ import print_function
 
 import optparse
@@ skipping 259 matching lines @@
     with open(options.out, "w") as out_file:
       for superinstruction in sorted(all_superinstructions):
         print(superinstruction, file=out_file)
   else:
     for superinstruction in sorted(all_superinstructions):
       print(superinstruction)
 
 
 if __name__ == '__main__':
   main()