ref: adding copyright headers and licensing files

Change-Id: I135f73159c3e010f7faf14f1215bbd74eb32c2cb
diff --git a/examples/tunnel/tunnelutil/terminal.go b/examples/tunnel/tunnelutil/terminal.go
index 92f178f..de51af0 100644
--- a/examples/tunnel/tunnelutil/terminal.go
+++ b/examples/tunnel/tunnelutil/terminal.go
@@ -1,3 +1,7 @@
+// Copyright 2015 The Vanadium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 // Package tunnelutil contains a set of common types and functions
 // used by both tunnel service clients and servers.
 package tunnelutil