HIVE-7912 : Don't add is not null filter for partitioning column (Ashutosh Chauhan via Harish Butani)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1621497 13f79535-47bb-0310-9956-ffa450edef68
HIVE-7876 : further improve the columns stats update speed for all the partitions of a table (Pengcheng Xiong via Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1621542 13f79535-47bb-0310-9956-ffa450edef68
HIVE-7911 : Guaranteed ClassCastException in AccumuloRangeGenerator (Lars Francke via Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1621544 13f79535-47bb-0310-9956-ffa450edef68