PIG-3838: Organize tez code into subpackages (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1626075 13f79535-47bb-0310-9956-ffa450edef68
PIG-3838: Organize tez code into subpackages (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1626077 13f79535-47bb-0310-9956-ffa450edef68