Update FlowManager's API design and define batch operation map's API.

- FlowManager returns FlowBatchHandle as a handler to the batch execution.
 -- addFlow(), removeFlow() and executeBatch() methods are executed asynchronously.
 -- Users can get the current state of the batch via the FlowBatchHandle.
- Defined FlowOperationMap's inital API designs.

This task is a part of ONOS-1687, ONOS-1842, and ONOS-1692.

Change-Id: Ic9e8ce3ab0378615d9d3016b7755ee6d15e1e47c
diff --git a/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerListener.java b/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerListener.java
index 0e70867..90ed2ca 100644
--- a/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerListener.java
+++ b/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerListener.java
@@ -1,5 +1,6 @@
 package net.onrc.onos.api.flowmanager;
 
+
 /**
  * An interface to the FlowManager's listener.
  */