[ONOS-3689] Implement skeleton of Neutron L3 service plugin

  - Added event handlers (Floatingip_CUD(Create, Update, Delete), Router_CUD, and RouterInterface_CUD).
  - Added packet handlers about ICMP and pNAT.
  - Added the models of openstack router, router interface, external gateway and floatingIP.
  - Fixed pom.xml
  - Added external_fixed_IP information for PNAT and renamed SNAT to PNAT in OpenstackExternalGateway
  - Fixed java docs in OpenstackRoutingService.java

Change-Id: Ia694614cf8885d81a66fc4659db2fa0c5de5e950
diff --git a/apps/openstackrouting/src/main/java/org/onosproject/openstackrouting/OpenstackFloatingIPHandler.java b/apps/openstackrouting/src/main/java/org/onosproject/openstackrouting/OpenstackFloatingIPHandler.java
new file mode 100644
index 0000000..4255f50
--- /dev/null
+++ b/apps/openstackrouting/src/main/java/org/onosproject/openstackrouting/OpenstackFloatingIPHandler.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2016 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.onosproject.openstackrouting;
+
+import org.onosproject.event.AbstractEvent;
+
+/**
+ * Handle FloatingIP Event for Managing Flow Rules In Openstack Nodes.
+ */
+public class OpenstackFloatingIPHandler implements Runnable {
+
+    volatile AbstractEvent event;
+    OpenstackFloatingIPHandler(AbstractEvent event) {
+        this.event = event;
+    }
+
+    @Override
+    public void run() {
+
+    }
+}