PIG-4048: TEZ-692 has a incompatible API change removing TezSession (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1608233 13f79535-47bb-0310-9956-ffa450edef68
PIG-3984: PigServer.shutdown removes the tez resource folder (daijy via rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1608292 13f79535-47bb-0310-9956-ffa450edef68