PIG-4145: Port local mode tests to Tez - part1

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1621922 13f79535-47bb-0310-9956-ffa450edef68
PIG-4144: Make pigunit.PigTest work in tez mode

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1621928 13f79535-47bb-0310-9956-ffa450edef68