Update the TopologyManager so it is now a module (IFloodlightModule).

NOTE: For the time being, there might be explicit TopologyManager
class instances created in places like the FlowManager.
diff --git a/conf/onos.properties b/conf/onos.properties
index c67b340..e858adb 100644
--- a/conf/onos.properties
+++ b/conf/onos.properties
@@ -9,6 +9,7 @@
 net.floodlightcontroller.ui.web.StaticWebRoutable,\
 net.onrc.onos.datagrid.HazelcastDatagrid,\
 net.onrc.onos.ofcontroller.flowmanager.FlowManager,\
+net.onrc.onos.ofcontroller.topology.TopologyManager,\
 net.onrc.onos.registry.controller.ZookeeperRegistry
 net.floodlightcontroller.restserver.RestApiServer.port = 8080
 net.floodlightcontroller.core.FloodlightProvider.openflowport = 6633