Take into account information about freshness and TLS support

[KOLANICH]

For Debian info about freshness is available on https://mirror-master.debian.org, though there is no info about TLS support, for info about TLS one has to probe each server.

Though I see no info present on the site available as JSON (or other serialization format, like CBOR) and I haven't found the source of the script generating that site. @weaselp, should I implement that feature and where can I find the source?