Migrate Gb (NS/BSSGP) code over to Ericsson NS/BSSGP modules

When we started out, Ericsson hadn't released yet their NS and BSSGP
modules.  Let's port our logic over to their encoder/decoders, as they
are more complete (but less regular / more difficult to use).

Change-Id: Icbc4f5d24f3419f99c9a4805f836bddd2849f492
diff --git a/library/NS_CodecPort.ttcn b/library/NS_CodecPort.ttcn
index 29f8aa5..82ba55b 100644
--- a/library/NS_CodecPort.ttcn
+++ b/library/NS_CodecPort.ttcn
@@ -2,7 +2,6 @@
 
 	import from IPL4asp_PortType all;
 	import from IPL4asp_Types all;
-	import from BSSGP_Helper_Functions all;
 	import from NS_Types all;
 
 	type record NS_RecvFrom {
@@ -11,10 +10,10 @@
 		PortNumber	remPort,
 		HostName	locName,
 		PortNumber	locPort,
-		NsPdu		msg
+		PDU_NS		msg
 	}
 
-	template NS_RecvFrom t_NS_RecvFrom(template NsPdu pdu) := {
+	template NS_RecvFrom t_NS_RecvFrom(template PDU_NS pdu) := {
 		connId := ?,
 		remName := ?,
 		remPort := ?,
@@ -25,10 +24,10 @@
 
 	type record NS_Send {
 		ConnectionId	connId,
-		NsPdu		msg
+		PDU_NS		msg
 	}
 
-	template NS_Send t_NS_Send(template ConnectionId connId, template NsPdu msg) := {
+	template NS_Send t_NS_Send(template ConnectionId connId, template PDU_NS msg) := {
 		connId := connId,
 		msg := msg
 	}
@@ -39,13 +38,13 @@
 		pout.remPort := pin.remPort;
 		pout.locName := pin.locName;
 		pout.locPort := pin.locPort;
-		pout.msg := dec_NsPdu(f_NS_expand_len(pin.msg));
+		pout.msg := dec_PDU_NS(pin.msg);
 	} with { extension "prototype(fast)" };
 
 	private function NS_to_IPL4_Send(in NS_Send pin, out ASP_Send pout) {
 		pout.connId := pin.connId;
 		pout.proto := { udp := {} };
-		pout.msg := f_NS_compact_len(enc_NsPdu(pin.msg));
+		pout.msg := enc_PDU_NS(pin.msg);
 	} with { extension "prototype(fast)" };
 
 	type port NS_CODEC_PT message {