Log TLS Cryptography Parameters

Log TLS Cryptography Parameters

This patch adds the following formatting codes:
  %ssl::>negotiated_version  The TLS version of the client-to-Squid connection.
  %ssl::<negotiated_version  The TLS version of the Squid-to-server connection.
  %ssl::>received_hello_version The TLS version of the Hello message received
                                from TLS client
  %ssl::<received_hello_version The TLS version of the Hello message received
                                from TLS server.
  %ssl::>received_supported_version The maximum TLS version supported by the
                                    the TLS client.
  %ssl::<received_supported_version The maximum TLS version supported by the
                                    the TLS server.
  %ssl::>cipher   The negotiated cipher of the client-to-Squid connection.
  %ssl::<cipher   The negotiated cipher of the Squid-to-server connection.

These are useful for statistics collection, security reviews, and reviews
prior to adjusting the list of the allowed TLS protocols and ciphers.

This is a Measurement Factory project