rename topology related objects: Device -> Host

- KVDevice to be renamed later.
- Use fully qualified name for topology's Host. (HostManager.java)

Change-Id: I1538f96d7ca93ca2197d23e5a69b85d284611412
diff --git a/src/main/java/net/onrc/onos/core/topology/SwitchEvent.java b/src/main/java/net/onrc/onos/core/topology/SwitchEvent.java
index 0464ffc..fdc4b84 100644
--- a/src/main/java/net/onrc/onos/core/topology/SwitchEvent.java
+++ b/src/main/java/net/onrc/onos/core/topology/SwitchEvent.java
@@ -12,7 +12,7 @@
 /**
  * Self-contained Switch Object.
  * <p/>
- * TODO: Rename to match what it is. (Switch/Port/Link/Device)Snapshot?
+ * TODO: Rename to match what it is. (Switch/Port/Link/Host)Snapshot?
  * FIXME: Current implementation directly use this object as
  *        Replication message, but should be sending update operation info.
  */