Creates a logger using the given settings.

def _create_logger(middleware_settings):
    """ Creates a logger using the given settings.
    """
    if django_settings.DEBUG:
        level = logging.DEBUG
        formatter = logging.Formatter(
            middleware_settings['LOGGER_FORMAT_DEBUG'])
    else:
        level = middleware_settings['LOGGER_LEVEL']
        formatter = logging.Formatter(middleware_settings['LOGGER_FORMAT'])

    handler = logging.StreamHandler(sys.stderr)
    handler.setLevel(level)
    handler.setFormatter(formatter)

    logger = logging.getLogger(middleware_settings['LOGGER_NAME'])

    # If in some strange way this logger already exists we make sure to delete
    # its existing handlers
    del logger.handlers[:]

    logger.addHandler(handler)

    # Disable propagation by default
    logger.propagate = False

    return logger