HIVE-5901 : Query cancel should stop running MR tasks (Navis via Thejas Nair)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1575527 13f79535-47bb-0310-9956-ffa450edef68
HIVE-6403 uncorrelated subquery is failing with auto.convert.join=true (Navis via Harish Butani)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1575572 13f79535-47bb-0310-9956-ffa450edef68