PIG-4157: Pig compilation failure due to HIVE-7208

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1623254 13f79535-47bb-0310-9956-ffa450edef68
PIG-4155: Quitting grunt shell using CTRL-D character throws exception

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1623272 13f79535-47bb-0310-9956-ffa450edef68
PIG-4154: ScriptState#setScript(File) does not close resources

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1623273 13f79535-47bb-0310-9956-ffa450edef68