HBASE-12617 Running IntegrationTestBigLinkedList against cluster getting not an instance of org.apache.hadoop.hbase.MiniHBaseCluster

(cherry picked from commit d6b1d8cbf7e11b51523cd0290243bce9cb22eb79)
HBASE-12624 Remove rename_snapshot.rb from code as there is no equivalent renameSnapshot api in Admin class (Ashish Singhi)
HBASE-11639 [Visibility controller] Replicate the visibility of Cells as
strings : Addendum adding break (Ram)
Add timeout on TestDefaultLoadBalancer#testBalancerCluster to see if we can stop it hanging as a zombie in precommit builds
HBASE-12431 Use of getColumnLatestCell(byte[], int, int, byte[], int, int) is Not Thread Safe (Jingcheng Du)

(cherry picked from commit c45772e76a581838ea89ff303d0ff67ceaa82845)