_ rendered as � in file names on files.interlisp.org

[pamoroso]

On the https://files.interlisp.org/medley/ website _ characters in file names are now rendered as � in Firefox and Chrome on Linux. The issue likely started no earlier than one or two weeks ago.

[masinter]

somehow the characdter codes that come back from DIRECTORY are mapped into UTF-8 when the external format of the index.html file that is produced.

We could patch this by being careful to set up the external format of the index.html stream and writing a CHARSET in the HTML head, but the defaults assumed by MAKE-INDEX-HTMLS are reasonable and shouldn't have broken.