Move Jedis CRC16 util as it's being used in the project.

Changed Makefile to cleanup redis cluster node configuration before running tests
Add cleanup to ClusterCommandTest.

Makefile

@@ -145,7 +145,7 @@ export REDIS_CLUSTER_NODE1_CONF
 export REDIS_CLUSTER_NODE2_CONF
 export REDIS_CLUSTER_NODE3_CONF
 
-start:
+start: cleanup
 	echo "$$REDIS1_CONF" | redis-server -
 	echo "$$REDIS2_CONF" | redis-server -
 	echo "$$REDIS3_CONF" | redis-server -
@@ -161,6 +161,9 @@ start:
 	echo "$$REDIS_CLUSTER_NODE2_CONF" | redis-server -
 	echo "$$REDIS_CLUSTER_NODE3_CONF" | redis-server -
 
+cleanup:
+	rm -vf /tmp/redis_cluster_node*.conf
+
 stop:
 	kill `cat /tmp/redis1.pid`
 	kill `cat /tmp/redis2.pid`