PIG-3048: Add mapreduce workflow information to job configuration

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1518788 13f79535-47bb-0310-9956-ffa450edef68
PIG-3048: Add mapreduce workflow information to job configuration

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1518800 13f79535-47bb-0310-9956-ffa450edef68
PIG-2606: union/ join operations are not accepting same alias as multiple inputs

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1518825 13f79535-47bb-0310-9956-ffa450edef68