PIG-3882: Multiquery off mode execution is not done in batch and very inefficient (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1586657 13f79535-47bb-0310-9956-ffa450edef68
PIG-3884: Move multi store counters to PigStatsUtil from MRPigStatsUtil (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1586720 13f79535-47bb-0310-9956-ffa450edef68