[tz] Data loss on FTP Server

[Zefram]

Paul Eggert wrote:
>I no longer recommend FTP to get tzdb.

HTTPS is fine for retrieving a specific release, but FTP offers a couple
of other facilities that AFAICS HTTPS doesn't provide.  Specifically, by
FTP I can enumerate old releases (NLST on the /tz/releases directory), and
I can identify the latest release (by processing the directory listing).
I've automated those jobs.  Is there a recommended way to do these things
through the HTTPS interface?  (Scraping a human-oriented web page isn't
an attractive approach.)

-zefram