CORD-349 Support VLAN cross-connect traffic

Change related to this topic:
- Support VLAN cross-connect traffic
    Utilize ports subjectClass to achieve. For non-xConnect port, set interface VLAN to -1
- Remove VLAN checking since we have multiple VLANs per port
- Hash the L2 interface group key generation to include VLAN as well
- Update the network-cfg.json sample

Other refactoring changes:
- Read next objective stores from srManager directly
- Use constant for flow priority
- CORD-267 Javadoc fix

Change-Id: I4ca8c2d9c8b3633a4a0101c5070d19343f7e5b90
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/ArpHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/ArpHandler.java
index 6d9171b..51324893 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/ArpHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/ArpHandler.java
@@ -41,6 +41,10 @@
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
+/**
+ * Handler of ARP packets that responses or forwards ARP packets that
+ * are sent to the controller.
+ */
 public class ArpHandler {
 
     private static Logger log = LoggerFactory.getLogger(ArpHandler.class);