Register flow-manager and match-action related classes to KryoFactory.

- The following classes are now registered and available on KryoFactory:
 -- FlowId
 -- Path
 -- Tree
 -- FlowLink
 -- OpticalPathFlow
 -- PacketPathFlow
 -- SingleDstTreeFlow
 -- PacketMatch
 -- OutputAction
 -- ModifyDstMacAction
 -- ModifyDstMacAction
- This task is a preperation for ONOS-1736 and ONOS-1842.

Change-Id: If438f5175e68672e0ce02f56681c35c3be87f0bc
diff --git a/src/main/java/net/onrc/onos/api/flowmanager/FlowLink.java b/src/main/java/net/onrc/onos/api/flowmanager/FlowLink.java
index 2fded10..8b8ad75 100644
--- a/src/main/java/net/onrc/onos/api/flowmanager/FlowLink.java
+++ b/src/main/java/net/onrc/onos/api/flowmanager/FlowLink.java
@@ -1,6 +1,7 @@
 package net.onrc.onos.api.flowmanager;
 
 import com.google.common.base.Objects;
+
 import net.onrc.onos.core.util.Dpid;
 import net.onrc.onos.core.util.PortNumber;
 import net.onrc.onos.core.util.SwitchPort;
@@ -16,6 +17,15 @@
     protected SwitchPort dstSwitchPort;
 
     /**
+     * Default constructor for Kryo deserialization.
+     */
+    @Deprecated
+    protected FlowLink() {
+        srcSwitchPort = null;
+        dstSwitchPort = null;
+    }
+
+    /**
      * Creates new FlowLink object using source/destination switch port pair.
      *
      * @param src The source switch port.