HBASE-12624 Remove rename_snapshot.rb from code as there is no equivalent renameSnapshot api in Admin class (Ashish Singhi)
HBASE-12431 Use of getColumnLatestCell(byte[], int, int, byte[], int, int) is Not Thread Safe (Jingcheng Du)
HBASE-12634 Fix the AccessController#requireGlobalPermission(ns) with NS

Signed-off-by: Matteo Bertozzi <matteo.bertozzi@cloudera.com>