CORD-176, CORD-431 Switch to new VTN API

- Implemented VTN store and manager to keep network states
- Implemented the new VTN API for service network and port

Change-Id: Id8f5d0e609fa3deba782ff2265fc0d3175cbcb4c
diff --git a/src/main/java/org/opencord/cordvtn/api/VtnNetworkListener.java b/src/main/java/org/opencord/cordvtn/api/VtnNetworkListener.java
new file mode 100644
index 0000000..be78ef0
--- /dev/null
+++ b/src/main/java/org/opencord/cordvtn/api/VtnNetworkListener.java
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.opencord.cordvtn.api;
+
+import org.onosproject.event.EventListener;
+
+/**
+ * Listener for vtn network event.
+ */
+public interface VtnNetworkListener extends EventListener<VtnNetworkEvent> {
+}