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/grouphandler/NeighborSetNextObjectiveStoreKey.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/NeighborSetNextObjectiveStoreKey.java
index 9ace531..ac33036 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/NeighborSetNextObjectiveStoreKey.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/grouphandler/NeighborSetNextObjectiveStoreKey.java
@@ -21,22 +21,38 @@
 import org.onosproject.net.DeviceId;
 
 /**
- * Class definition of Key for Neighborset to NextObjective store.
+ * Key of Neighborset next objective store.
  */
 public class NeighborSetNextObjectiveStoreKey {
     private final DeviceId deviceId;
     private final NeighborSet ns;
 
+    /**
+     * Constructs the key of neighbor set next objective store.
+     *
+     * @param deviceId device ID
+     * @param ns neighbor set
+     */
     public NeighborSetNextObjectiveStoreKey(DeviceId deviceId,
                                             NeighborSet ns) {
         this.deviceId = deviceId;
         this.ns = ns;
     }
 
+    /**
+     * Returns the device ID in the key.
+     *
+     * @return device ID
+     */
     public DeviceId deviceId() {
         return this.deviceId;
     }
 
+    /**
+     * Returns the neighbor set in the key.
+     *
+     * @return neighbor set
+     */
     public NeighborSet neighborSet() {
         return this.ns;
     }