Refactor the TopologyManager:

 * Moved the Shortest Path computations to new class ShortestPath
   inside file  topology/ShortestPath.java
 * Moved the topology-related state to new class Topology
   inside file  topology/Topology.java
 * Renamed/cleanup the TopologyManager API:
   - prepareShortestPathTopo() -> newDatabaseTopology()
   - dropShortestPathTopo() -> dropTopology()
   - getTopoShortestPath() -> getTopologyShortestPath()
   - getShortestPath() -> getDatabaseShortestPath()
diff --git a/src/main/java/net/onrc/onos/ofcontroller/util/DataPath.java b/src/main/java/net/onrc/onos/ofcontroller/util/DataPath.java
index e807b56..7c6597d 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/util/DataPath.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/util/DataPath.java
@@ -105,8 +105,8 @@
      * computation.
      *
      * NOTE: This method assumes the DataPath was created by
-     * using FlowManager::getShortestPath() so the inPort and outPort
-     * of the Flow Entries are set.
+     * using the TopologyManager shortest path computation, so the inPort
+     * and outPort of the Flow Entries are set.
      * NOTE: This method is a temporary solution and will be removed
      * in the future.
      *