Parses optional command line arguments.

def read_cmdline():
    """
    Parses optional command line arguments.
    """
    info = {
            "prog": "Ellis",
            "description": "%(prog)s version {0}".format(__version__),
            "epilog": "For further help please head over to {0}"
                      .format(__url__),
            "usage": argparse.SUPPRESS,
    }

    argp = argparse.ArgumentParser(**info)

    # Add an optional string argument 'config':
    argp.add_argument("-c", "--config",
                      dest='config_file',
                      metavar='FILE',
                      help="read configuration from FILE",
                      type=str)

    # Parse command line:
    args = argp.parse_args()

    return vars(args)