PIG-3424: Fix test failure for import order change fix

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1516532 13f79535-47bb-0310-9956-ffa450edef68
PIG-3168: Revert the behavior of explain with no alias


git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1516545 13f79535-47bb-0310-9956-ffa450edef68