CBST-22: restart nodes after failover

when a node is failed over it is still in the pool of nodes that can be added back to cluster, but since we stopped couchbase on the node, add_back will fail. so after node is rebalanced out, we should restart couchbase so that node can be reused.

Change-Id: Iefbb714bff78b34d744e54682a6daf6542465bc1
Reviewed-on: http://review.couchbase.org/30630
Reviewed-by: Tommie McAfee <tommie@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>