Rearrange Cluster node for full 1on1 replicate

* move cluster node 4 to cluster node 7
* add cluster node 4, 5, 6
Fix Makefile : cleaning
CLUSTER REPLICATE / CLUSTER SLAVES

* CLUSTER REPLICATE : setup master/slave relation between cluster nodes
** usage : CLUSTER REPLICATE <nodeId>
* CLUSTER SLAVES : get specific node's slaves information
** usage : CLUSTER SLAVES <nodeId>
** information content is same to cluster nodes, but per slave
*** no need to split to "\n"
* Unit test included (separated to JedisClusterTest)
** JedisClusterTestUtil: place common utility methods