Revert "Remove heartbeats completely"

Done too soon, this is for future OpenSSL 1.2.0

This reverts commit 6c62f9e1639a7d1a879f363a99882920104dfedb.

Reviewed-by: Rich Salz <rsalz@openssl.org>

ssl/t1_trce.c

diff --git a/ssl/t1_trce.c b/ssl/t1_trce.c
index e12a4a8..2e94c65 100644
--- a/ssl/t1_trce.c
+++ b/ssl/t1_trce.c
@@ -710,6 +710,9 @@
         }
         break;
 
+    case TLSEXT_TYPE_heartbeat:
+        return 0;
+
     case TLSEXT_TYPE_session_ticket:
         if (extlen != 0)
             ssl_print_hex(bio, indent + 4, "ticket", ext, extlen);