Add TLS exporter.

ssl/d1_lib.c

diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
index c3b77c8..a94290a 100644
--- a/ssl/d1_lib.c
+++ b/ssl/d1_lib.c
@@ -82,6 +82,7 @@
 	TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
 	TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
 	tls1_alert_code,
+	tls1_export_keying_material,
 	};
 
 long dtls1_default_timeout(void)