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

site_scons/site_tools/target_platform_windows.py

-#!/usr/bin/python2.4
+#!/usr/bin/env python
 # Copyright 2009, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 417 matching lines @@
   )
 
   # TODO: mslink.py creates a shlibLinkAction which doesn't specify
   # '$SHLINKCOMSTR' as its command string.  This breaks --brief.  For now,
   # hack into the existing action and override its command string.
   if use_msvc_tools:
     env['SHLINKCOM'].list[0].cmdstr = '$SHLINKCOMSTR'
 
   # Restore saved flags.
   env.Append(**saved)