Work toward ONOS-1451: Separate Event Key space per instance

Misc changes and cleanup:
* Added new class OnosInstanceId
* Replace (as appropriate) the string controllerId (and associated methods)
  with the new class OnosInstanceId
* Renaming: Host -> Device
  - Method getDeviceID -> getHostID
  - Changed Host Key ID prefix 'D' to 'H'
  - Few renaming of Host -> Device inside Javadoc

Change-Id: I59c20d68277ecde2f7df4e7097a4a52d5786df1b
diff --git a/src/main/java/net/onrc/onos/core/util/serializers/KryoFactory.java b/src/main/java/net/onrc/onos/core/util/serializers/KryoFactory.java
index 47b2349..4ab832e 100644
--- a/src/main/java/net/onrc/onos/core/util/serializers/KryoFactory.java
+++ b/src/main/java/net/onrc/onos/core/util/serializers/KryoFactory.java
@@ -56,6 +56,7 @@
 import net.onrc.onos.core.util.IPv6;
 import net.onrc.onos.core.util.IPv6Net;
 import net.onrc.onos.core.util.LinkTuple;
+import net.onrc.onos.core.util.OnosInstanceId;
 import net.onrc.onos.core.util.PortNumber;
 import net.onrc.onos.core.util.Switch;
 import net.onrc.onos.core.util.SwitchPort;
@@ -201,18 +202,19 @@
         kryo.register(LinkTuple.class);
 
         // New data model-related classes
+        kryo.register(AdminStatus.class);
+        kryo.register(ConcurrentHashMap.class);
+        kryo.register(ConfigState.class);
         kryo.register(HostEvent.class);
         kryo.register(LinkedList.class);
         kryo.register(LinkEvent.class);
         kryo.register(MastershipEvent.class);
+        kryo.register(OnosInstanceId.class);
         kryo.register(PortEvent.class);
         kryo.register(Role.class);
         kryo.register(SwitchEvent.class);
-        kryo.register(TopologyEvent.class);
         kryo.register(TopologyElement.class);
-        kryo.register(ConcurrentHashMap.class);
-        kryo.register(ConfigState.class);
-        kryo.register(AdminStatus.class);
+        kryo.register(TopologyEvent.class);
 
         // Intent-related classes
         kryo.register(Path.class);