More HostMonitor cleanup and javadocs
diff --git a/core/net/src/main/java/org/onlab/onos/net/host/impl/HostManager.java b/core/net/src/main/java/org/onlab/onos/net/host/impl/HostManager.java
index 88b6923..29a0f18 100644
--- a/core/net/src/main/java/org/onlab/onos/net/host/impl/HostManager.java
+++ b/core/net/src/main/java/org/onlab/onos/net/host/impl/HostManager.java
@@ -76,7 +76,7 @@
         eventDispatcher.addSink(HostEvent.class, listenerRegistry);
 
         monitor = new HostMonitor(deviceService,  packetService, this);
-
+        monitor.start();
     }
 
     @Deactivate