Added new API to the IDatagridService to get/lookup a Flow or a Flow Entry
for a given Flow ID or Flow Entry ID respectively. Implement
the API for Hazelcast:

 * getFlow(FlowId flowId)
 * getFlowEntry(FlowEntryId flowEntryId)
diff --git a/src/main/java/net/onrc/onos/datagrid/IDatagridService.java b/src/main/java/net/onrc/onos/datagrid/IDatagridService.java
index 9361341..034fe25 100644
--- a/src/main/java/net/onrc/onos/datagrid/IDatagridService.java
+++ b/src/main/java/net/onrc/onos/datagrid/IDatagridService.java
@@ -50,7 +50,7 @@
      * @param arpEventHandler The ARP event handler to de-register.
      */
     public void deregisterArpEventHandler(IArpEventHandler arpEventHandler);
-    
+
     /**
      * Get all Flows that are currently in the datagrid.
      *
@@ -59,6 +59,14 @@
     Collection<FlowPath> getAllFlows();
 
     /**
+     * Get a Flow for a given Flow ID.
+     *
+     * @param flowId the Flow ID of the Flow to get.
+     * @return the Flow if found, otherwise null.
+     */
+    FlowPath getFlow(FlowId flowId);
+
+    /**
      * Send a notification that a Flow is added.
      *
      * @param flowPath the Flow that is added.
@@ -92,6 +100,14 @@
     Collection<FlowEntry> getAllFlowEntries();
 
     /**
+     * Get a Flow Entry for a given Flow Entry ID.
+     *
+     * @param flowEntryId the Flow Entry ID of the Flow Entry to get.
+     * @return the Flow Entry if found, otherwise null.
+     */
+    FlowEntry getFlowEntry(FlowEntryId flowEntryId);
+
+    /**
      * Send a notification that a FlowEntry is added.
      *
      * @param flowEntry the FlowEntry that is added.