Get a sorted list of all CommandLineOption subclasses.

def gather_command_line_options(filter_disabled=None):
    """Get a sorted list of all CommandLineOption subclasses."""
    if filter_disabled is None:
        filter_disabled = not SETTINGS.COMMAND_LINE.SHOW_DISABLED_OPTIONS
    options = [opt for opt in get_inheritors(CommandLineOption)
               if not filter_disabled or opt._enabled]
    return sorted(options, key=lambda opt: opt.__name__)