* more refined yaml reading options: url with/without sig and checksum. with multuple copy destinations.
    * removed redundant functions get_machine_config_file_path, get_user_config_file_path
    * Split new function read_from_file_or_url from download_from_file_or_url
    * new initial vars: "__SITE_DATA_DIR__": appdirs.site_data_dir(),
                        "__SITE_CONFIG_DIR__": appdirs.site_config_dir(),
                        "__USER_DATA_DIR__": appdirs.user_data_dir(),
                         "__USER_CONFIG_DIR__": appdirs.user_config_dir()