Fix javadoc:javadoc warnings

- Exclude org.openflow.* from generated javadoc
- Fix warnings

Change-Id: I47aefff15582c6eec05b864fb19613200d07df03
diff --git a/src/main/java/net/onrc/onos/core/topology/TopologyEvent.java b/src/main/java/net/onrc/onos/core/topology/TopologyEvent.java
index cf61017..81e261d 100644
--- a/src/main/java/net/onrc/onos/core/topology/TopologyEvent.java
+++ b/src/main/java/net/onrc/onos/core/topology/TopologyEvent.java
@@ -60,7 +60,8 @@
 
     /**
      * Check if all events contained are equal.
-     * @param obj.
+     *
+     * @param obj TopologyEvent to compare against
      */
     @Override
     public boolean equals(Object obj) {