Added support for class hierarchies in the notification system.
This is done using Kryo's writeClassAndObject/readClassAndObject, which
doesn't rely on the caller specifying the class.

Also, paramterized the Class class in some places to prevent Java warning
about using raw types.

Change-Id: Ib05465c412bf7fe0c3269896cc20527082f591a6
diff --git a/src/main/java/net/onrc/onos/core/datagrid/IEventChannel.java b/src/main/java/net/onrc/onos/core/datagrid/IEventChannel.java
index 5874b31..0c1663a 100644
--- a/src/main/java/net/onrc/onos/core/datagrid/IEventChannel.java
+++ b/src/main/java/net/onrc/onos/core/datagrid/IEventChannel.java
@@ -24,7 +24,7 @@
      * @return true if the key and value types of the channel match,
      * otherwise false.
      */
-    boolean verifyKeyValueTypes(Class typeK, Class typeV);
+    boolean verifyKeyValueTypes(Class<?> typeK, Class<?> typeV);
 
     /**
      * Add event channel listener.