[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/pom.xml b/apps/pom.xml
index 79e7466..ae99224 100644
--- a/apps/pom.xml
+++ b/apps/pom.xml
@@ -65,6 +65,7 @@
         <module>cpman</module>
         <module>events</module>
         <module>vrouter</module>
+        <module>openstackrouting</module>
   </modules>
 
     <properties>