CORD-348 multicast support in SegmentRouting and vRouter

In this submission:
* Setup/teardown multicast route according to SinkAdded/SinkRemoved event
    - ingressVlan and egressVlan is configurable through network config
* Change behavior of OFDPA VLAN assignment
    - Always use the VLAN in metadata if present
* Bugfix of writing immutable object

NOT in this submission (coming soon):
* Error handling (e.g. link/device failure recovery)

Change-Id: I9be11af04eb2d6456b865c7e59e96cc02370f846
diff --git a/BUCK b/BUCK
index 68b76d0..f532bea 100644
--- a/BUCK
+++ b/BUCK
@@ -3,9 +3,9 @@
     '//lib:org.apache.karaf.shell.console',
     '//lib:javax.ws.rs-api',
     '//cli:onos-cli',
+    '//core/store/serializers:onos-core-serializers',
     '//incubator/api:onos-incubator-api',
     '//utils/rest:onlab-rest',
-    '//core/store/serializers:onos-core-serializers',
 ]
 
 TEST_DEPS = [