Note: help and version output are generated by a naïve script which tries a few variants of
<command> --help, <command> -h etc. to find the command's help and version info.
Sometimes it gets lucky, sometimes it doesn't; if the output below looks wrong, it probably is.
dwww-cache -V (return code: 1)
dwww-cache: unrecognized option '--version'
dwww-cache --help (return code: 0)
Usage: dwww-cache [--lookup|--store|--list] type location
dwww-cache --list-all|--clean|--help