Configure ZooKeeper connection to ONOS/RAMCloud

- ZooKeeper server list specified by zookeeper.hosts (onos_node.conf)
  will be used as ZooKeeper fallback connection list for
  ONOS, RAMCloud. (ONOS-1756)

Change-Id: Iaef6bee82a28f3181f3fc681707666033f8d746f
diff --git a/conf/onos_node.conf b/conf/onos_node.conf
index 19c6ae6..3607585 100644
--- a/conf/onos_node.conf
+++ b/conf/onos_node.conf
@@ -20,10 +20,18 @@
 host.backend = hazelcast
 #host.backend = ramcloud
 
+# ZooKeeper: port to listen for client connections/
+#            port that clients attemApt to connect to
+#            (2181 by default)
+#zookeeper.clientPort = 2181
+
 # List of host name/IPs that constitute ZooKeeper cluster (only current host by default)
 # myid will be assigned incrementally according to order of list
 #zookeeper.hosts = onosdev1,onosdev2,onosdev3,onosdev4
 
+# ZooKeeper: ports to be used as leader, leader election. (2888:3888 by default)
+#zookeeper.ports = 2888:3888
+
 # RAMCloud clusterName (same as onos.cluster.name by default)
 #ramcloud.clusterName = onos