PIG-4114: Add Native operator to tez

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1617798 13f79535-47bb-0310-9956-ffa450edef68
PIG-4123: Increase memory for TezMiniCluster

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1617800 13f79535-47bb-0310-9956-ffa450edef68