Implement event listeners of the FlowManager.

- This commit adds two types of event objects: FlowBatchStateChangedEvent and FlowStatesChangedEvent.
- Listeners for these objects are defined by FlowManagerListener interface.
- FlowBatchStateChangedEvent notifies state changes of the flow batch operation.
 -- The state is defined by FlowBatchState.
- FlowStatesChangedEvent notifies state changes of the set of Flow objects.
 -- The state is defined by FlowState.
- This task is a part of ONOS-1739.

Change-Id: Ie8b3bb1c58dbe6bc608936e4a269e1de12dee96c
diff --git a/src/main/java/net/onrc/onos/core/flowmanager/FlowManagerModule.java b/src/main/java/net/onrc/onos/core/flowmanager/FlowManagerModule.java
index 2d184f8..8336095 100644
--- a/src/main/java/net/onrc/onos/core/flowmanager/FlowManagerModule.java
+++ b/src/main/java/net/onrc/onos/core/flowmanager/FlowManagerModule.java
@@ -1,12 +1,12 @@
 package net.onrc.onos.core.flowmanager;
 
 import java.util.Collection;
-import java.util.EventListener;
 
 import net.onrc.onos.api.flowmanager.ConflictDetectionPolicy;
+import net.onrc.onos.api.flowmanager.Flow;
 import net.onrc.onos.api.flowmanager.FlowBatchOperation;
 import net.onrc.onos.api.flowmanager.FlowId;
-import net.onrc.onos.api.flowmanager.Flow;
+import net.onrc.onos.api.flowmanager.FlowManagerListener;
 import net.onrc.onos.api.flowmanager.FlowManagerService;
 
 /**
@@ -73,13 +73,13 @@
     }
 
     @Override
-    public void addEventListener(EventListener listener) {
+    public void addListener(FlowManagerListener listener) {
         // TODO Auto-generated method stub
 
     }
 
     @Override
-    public void removeEventListener(EventListener listener) {
+    public void removeListener(FlowManagerListener listener) {
         // TODO Auto-generated method stub
 
     }
diff --git a/src/main/java/net/onrc/onos/core/flowmanager/FlowOperationMap.java b/src/main/java/net/onrc/onos/core/flowmanager/FlowOperationMap.java
new file mode 100644
index 0000000..744c65e
--- /dev/null
+++ b/src/main/java/net/onrc/onos/core/flowmanager/FlowOperationMap.java
@@ -0,0 +1,8 @@
+package net.onrc.onos.core.flowmanager;
+
+/**
+ * Manages the set of flow operations throughout the ONOS instances.
+ */
+public class FlowOperationMap {
+    // TODO implement it
+}