HIVE-4985 : refactor/clean up partition name pruning to be usable inside metastore server (Sergey Shelukhin via Ashutosh Chauhan)

git-svn-id: https://svn.apache.org/repos/asf/hive/trunk@1513596 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd