Add port_forwarding to devstack plugin

This commit adds possibility to configure fip port_forwarding
service plugin and l3 extension with devstack plugin.

Change-Id: If01dd1db1b4a44ba2f7e2d8f8326e331f9dc79e9

devstack/lib/fip_port_forwarding

@@ -0,0 +1,4 @@
+function configure_port_forwarding {
+    neutron_service_plugin_class_add "port_forwarding"
+    plugin_agent_add_l3_agent_extension "port_forwarding"
+}

devstack/plugin.sh

@@ -11,6 +11,7 @@ source $LIBDIR/ovs
 source $LIBDIR/segments
 source $LIBDIR/trunk
 source $LIBDIR/log
+source $LIBDIR/fip_port_forwarding
 
 Q_BUILD_OVS_FROM_GIT=$(trueorfalse False Q_BUILD_OVS_FROM_GIT)
 
@@ -68,6 +69,9 @@ if [[ "$1" == "stack" ]]; then
                 if is_service_enabled q-qos neutron-qos; then
                     configure_l3_agent_extension_fip_qos
                 fi
+                if is_service_enabled q-port-forwarding neutron-port-forwarding; then
+                    configure_port_forwarding
+                fi
                 configure_l3_agent
             fi
             if [ $NEUTRON_CORE_PLUGIN = ml2 ]; then