Updates for SDN-IP:

 * Use the new Leadership Service instead of Distributed Lock to
   elect the SDN-IP Leader
 * Reimplement the SDN-IP Intent Synchronizer. In the new implementation
   the Point-to-Point Peer intents are also synchronized by and pushed
   only by the Leader (same as the Multipoint-to-SinglePoint Route intents)
 * Minor cleanups

Change-Id: I8e142781211a1d0f2d362875bc28fd05d843cd4b
diff --git a/pom.xml b/pom.xml
index 508b681..eec0ad7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -139,6 +139,12 @@
             </dependency>
 
             <dependency>
+                <groupId>org.apache.commons</groupId>
+                <artifactId>commons-collections4</artifactId>
+                <version>4.0</version>
+            </dependency>
+
+            <dependency>
                 <groupId>org.codehaus.jackson</groupId>
                 <artifactId>jackson-core-asl</artifactId>
                 <version>1.9.13</version>