Added package javadocs.

+/**
+ * Subsystem for tracking controller cluster nodes.
+ */
+package org.onlab.onos.cluster.impl;
\ No newline at end of file

+/**
+ * Implementation of a distributed cluster node store using Hazelcast.
+ */
+package org.onlab.onos.store.cluster.impl;
\ No newline at end of file

+/**
+ * Common abstractions and facilities for implementing distributed store
+ * using Hazelcast.
+ */
+package org.onlab.onos.store;
\ No newline at end of file

@@ -392,7 +392,7 @@
                         <group>
                             <title>Core Subsystems</title>
                             <packages>
-                                org.onlab.onos.net.device.impl:org.onlab.onos.net.link.impl:org.onlab.onos.net.host.impl:org.onlab.onos.net.topology.impl:org.onlab.onos.net.packet.impl:org.onlab.onos.net.flow.impl:org.onlab.onos.net.trivial.*:org.onlab.onos.net.*.impl:org.onlab.onos.cluster:org.onlab.onos.event.impl:org.onlab.onos.store.*
+                                org.onlab.onos.cluster.impl:org.onlab.onos.store:org.onlab.onos.net.device.impl:org.onlab.onos.net.link.impl:org.onlab.onos.net.host.impl:org.onlab.onos.net.topology.impl:org.onlab.onos.net.packet.impl:org.onlab.onos.net.flow.impl:org.onlab.onos.net.trivial.*:org.onlab.onos.net.*.impl:org.onlab.onos.cluster:org.onlab.onos.event.impl:org.onlab.onos.store.*
                             </packages>
                         </group>
                         <group>