HIVE-7526: Research to use groupby transformation to replace Hive existing partitionByKey and SparkCollector combination [Spark Branch]

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1614825 13f79535-47bb-0310-9956-ffa450edef68
HIVE-7526: Research to use groupby transformation to replace Hive existing partitionByKey and SparkCollector combination [Spark Branch] (missing new files and deleted file

git-svn-id: https://svn.apache.org/repos/asf/hive/branches/spark@1614850 13f79535-47bb-0310-9956-ffa450edef68
merge upstream