PATHNM changes and you

[Richard M. Stallman <RMS at MIT-AI>]

    If you still want to use a directory stream, you should define what is
    now READ-DIRECTORY-STREAM-ENTRY to be a message to pathnames,

I defined an operation :DIRECTORY-STREAM-DEFAULT-PARSER, which for
chaos-pathnames returns #'substring and for remote-data-pathnames
returns #'parse-random-sexp.