Move Path to intent package.

It's a bit confusing to have Path object, which is not part of Topology
under topology package.
Moving Path to intent package, since it started as a data structure for Path Intents

Stop inheriting Collection class.

Change-Id: Iaaa07e5f102bb12ad814db0be47bcfac536781e8
diff --git a/src/main/java/net/onrc/onos/core/util/serializers/KryoFactory.java b/src/main/java/net/onrc/onos/core/util/serializers/KryoFactory.java
index a1c4728..3d7f4aa 100644
--- a/src/main/java/net/onrc/onos/core/util/serializers/KryoFactory.java
+++ b/src/main/java/net/onrc/onos/core/util/serializers/KryoFactory.java
@@ -15,6 +15,7 @@
 import net.onrc.onos.core.intent.Intent;
 import net.onrc.onos.core.intent.IntentOperation;
 import net.onrc.onos.core.intent.IntentOperationList;
+import net.onrc.onos.core.intent.Path;
 import net.onrc.onos.core.intent.PathIntent;
 import net.onrc.onos.core.intent.ShortestPathIntent;
 import net.onrc.onos.core.intent.runtime.IntentStateList;
@@ -23,7 +24,6 @@
 import net.onrc.onos.core.packetservice.SinglePacketOutNotification;
 import net.onrc.onos.core.topology.DeviceEvent;
 import net.onrc.onos.core.topology.LinkEvent;
-import net.onrc.onos.core.topology.Path;
 import net.onrc.onos.core.topology.PortEvent;
 import net.onrc.onos.core.topology.SwitchEvent;
 import net.onrc.onos.core.topology.TopologyEvent;
@@ -52,6 +52,7 @@
 import net.onrc.onos.core.util.Switch;
 // import net.onrc.onos.core.util.SwitchPort;
 
+
 import com.esotericsoftware.kryo.Kryo;
 
 /**