yahns 1.14.0 - removing undefined behavior

There's minor feature removals for undocumented and
undefined features and behavior which are unlikely to
affect anybody unless they serve HTTPS.

Our website is now self-hosted with HTTPS support (HTTP remains
supported for legacy systems):

	https://yhbt.net/yahns/README

See git history at git://yhbt.net/yahns.git for full details.

      openssl_client: avoid undefined SSL_write behavior
      move website to https://yhbt.net/yahns/
      stream_file: remove #to_io support from responses
      response: only stream "file" responses on known length
      response: fixup compile error
      req_res: do not send 502 on catchall error if response buffered