[CORD-2838][CORD-2833] Revisit McastHandler and handle shortest paths with pair links

Includes also a refactoring of the path computation

Change-Id: Iff63780a3bb3e895e55c52211290c19d993e1905
diff --git a/app/BUCK b/app/BUCK
index 9674f76..41ae39c 100644
--- a/app/BUCK
+++ b/app/BUCK
@@ -8,6 +8,8 @@
     '//core/store/serializers:onos-core-serializers',
     '//incubator/api:onos-incubator-api',
     '//apps/route-service/api:onos-apps-route-service-api',
+    '//apps/mcast/api:onos-apps-mcast-api',
+    '//apps/mcast/cli:onos-apps-mcast-cli',
 ]
 
 TEST_DEPS = [