Remove TLS heartbeat, disable DTLS heartbeat

To enable heartbeats for DTLS, configure with enable-heartbeats.
Heartbeats for TLS have been completely removed.

This addresses RT 3647

Reviewed-by: Richard Levitte <levitte@openssl.org>

apps/openssl.c

@@ -748,6 +748,9 @@ static void list_disabled(void)
 #ifdef OPENSSL_NO_GOST
     BIO_puts(bio_out, "GOST\n");
 #endif
+#ifdef OPENSSL_NO_HEARTBEATS
+    BIO_puts(bio_out, "HEARTBEATS\n");
+#endif
 #ifdef OPENSSL_NO_HMAC
     BIO_puts(bio_out, "HMAC\n");
 #endif