HIVE-4540 JOIN-GRP BY-DISTINCT fails with NPE when mapjoin.mapreduce=true (Gunther Hagleitner via Navis)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1486721 13f79535-47bb-0310-9956-ffa450edef68
HIVE-4572 ColumnPruner cannot preserve RS key columns corresponding to un-selected join keys in columnExprMap (Yin Huai via Navis)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1486722 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-GEN-TESTS-SPLIT-trunk-gd