HIVE-7506 : MetadataUpdater: provide a mechanism to edit the statistics of a column in a table (or a partition of a table) (Pengcheng Xiong via Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1617889 13f79535-47bb-0310-9956-ffa450edef68