PIG-3299: Provide support for LazyOutputFormat to avoid creating empty files

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1564016 13f79535-47bb-0310-9956-ffa450edef68
PIG-3238: Pig current releases lack a UDF Stuff(). This UDF deletes a specified length of characters and inserts another set of characters at a specified starting point

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1564034 13f79535-47bb-0310-9956-ffa450edef68
PIG-2672: Optimize the use of DistributedCache (aniket486)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1564091 13f79535-47bb-0310-9956-ffa450edef68