Add more detail to the layout test server cli_wrapper command help.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/servers/cli_wrapper.py

 # Copyright (C) 2010 Google Inc. All rights reserved.
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 # in the documentation and/or other materials provided with the
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 # contributors may be used to endorse or promote products derived from
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 #
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-"""A utility script for starting and stopping servers as they are used in the layout tests."""
+"""A utility module for making standalone scripts to start servers.
+
+Scripts in Tools/Scripts can use this module to start servers that
+are normally used for layout tests, outside of the layout test runner.
+"""
 
 import logging
-import optparse
+import argparse
 
 from webkitpy.common.host import Host
 
 _log = logging.getLogger(__name__)
 
 
 def main(server_constructor, input_fn=None, argv=None, **kwargs):
     input_fn = input_fn or raw_input
 
-    option_parser = optparse.OptionParser()
-    option_parser.add_option('--output-dir', dest='output_dir',
-                             default=None, help='output directory.')
-    option_parser.add_option('-v', '--verbose', action='store_true')
-    options, args = option_parser.parse_args(argv)
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--output-dir', type=str, default=None,
+                        help='output directory, for log files etc.')
+    parser.add_argument('-v', '--verbose', action='store_true',
+                        help='print more information, including port numbers')
+    args = parser.parse_args(argv)
 
     logging.basicConfig()
     logger = logging.getLogger()
-    logger.setLevel(logging.DEBUG if options.verbose else logging.INFO)
+    logger.setLevel(logging.DEBUG if args.verbose else logging.INFO)
 
     host = Host()
     port_obj = host.port_factory.get()
-    if not options.output_dir:
-        options.output_dir = port_obj.default_results_directory()
+    if not args.output_dir:
+        args.output_dir = port_obj.default_results_directory()
 
     # Create the output directory if it doesn't already exist.
-    port_obj.host.filesystem.maybe_make_directory(options.output_dir)
+    port_obj.host.filesystem.maybe_make_directory(args.output_dir)
 
-    server = server_constructor(port_obj, options.output_dir, **kwargs)
+    server = server_constructor(port_obj, args.output_dir, **kwargs)
     server.start()
     try:
         _ = input_fn('Hit any key to stop the server and exit.')
     except (KeyboardInterrupt, EOFError) as e:
         pass
 
     server.stop()