Added Host related memos.

Change-Id: Idbbce6a72b6f7fecc6691f2af68f4ce40b58ca34
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/host/impl/GossipHostStore.java b/core/store/dist/src/main/java/org/onlab/onos/store/host/impl/GossipHostStore.java
index 8b5db8a..e20af88 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/host/impl/GossipHostStore.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/host/impl/GossipHostStore.java
@@ -43,6 +43,7 @@
 import static org.onlab.onos.net.host.HostEvent.Type.*;
 import static org.slf4j.LoggerFactory.getLogger;
 
+//TODO: multi-provider, annotation not supported.
 /**
  * Manages inventory of end-station hosts in distributed data store
  * that uses optimistic replication and gossip based techniques.