'Load a saved DownloadStartupConfig from disk.
@param filename  An absolute Unicode filename
@return DownloadStartupConfig object'

def load(filename):

    dlconfig = CallbackConfigParser()
    try:
        dlconfig.read_file(filename)
    except (ParsingError, IOError, MissingSectionHeaderError):
        logger.error('Failed    to    open    download    config    file:    %s', filename)
        raise
    return DownloadStartupConfig(dlconfig)
