+PP/16 Removed "dont_insert_empty_fragments" fron "openssl_options".
+ Removed SSL_clear() after SSL_new() which led to protocol negotiation
+ failures. We appear to now support TLS1.1+ with Exim.
+
+PP/17 OpenSSL: new expansion var $tls_sni, which if used in tls_certificate
+ lets Exim select keys and certificates based upon TLS SNI from client.
+ Also option tls_sni on SMTP Transports. Also clear $tls_bits correctly
+ before an outbound SMTP session. New log_selector, +tls_sni.
+