add help

fetch.py

 #!/usr/bin/env python
 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 Tool to perform checkouts in one easy command line!
 
 Usage:
   fetch <recipe> [--property=value [--property2=value2 ...]]
@@ skipping 138 matching lines @@
 """
 usage: %s <recipe> [--property=value [--property2=value2 ...]]
 """ % os.path.basename(sys.argv[0]))
   sys.exit(bool(msg))
 
 
 def handle_args(argv):
   """Gets the recipe name from the command line arguments."""
   if len(argv) <= 1:
     usage('Must specify a recipe.')
+  if argv[1] in ('-h', '--help', 'help'):
+    usage()
 
   def looks_like_arg(arg):
     return arg.startswith('--') and arg.count('=') == 1
 
   bad_parms = [x for x in argv[2:] if not looks_like_arg(x)]
   if bad_parms:
     usage('Got bad arguments %s' % bad_parms)
 
   recipe = argv[1]
   props = argv[2:]
@@ skipping 41 matching lines @@
 
 
 def main():
   recipe, props = handle_args(sys.argv)
   spec, root = run_recipe_fetch(recipe, props)
   return run(spec, root)
 
 
 if __name__ == '__main__':
   sys.exit(main())