Add comments with short module description on top of each file

Change-Id: Id934d7a763b619d52cbec7de439b3708225b81f3
diff --git a/library/MGCP_CodecPort.ttcn b/library/MGCP_CodecPort.ttcn
index 06072af..416ac36 100644
--- a/library/MGCP_CodecPort.ttcn
+++ b/library/MGCP_CodecPort.ttcn
@@ -1,5 +1,16 @@
 module MGCP_CodecPort {
 
+/* Simple MGCP Codec Port, translating between raw UDP primitives with
+ * octetstring payload towards the IPL4asp provider, and MGCP primitives
+ * which carry the decoded MGCP data types as payload.
+ *
+ * (C) 2017 by Harald Welte <laforge@gnumonks.org>
+ * All rights reserved.
+ *
+ * Released under the terms of GNU General Public License, Version 2 or
+ * (at your option) any later version.
+ */
+
 	import from IPL4asp_PortType all;
 	import from IPL4asp_Types all;
 	import from MGCP_Types all;