PIG-3654: Add class cache to PigContext

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1560468 13f79535-47bb-0310-9956-ffa450edef68
PIG-3654: Add class cache to PigContext

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1560469 13f79535-47bb-0310-9956-ffa450edef68
PIG-2207: Support custom counters for aggregating warnings from different udfs (aniket486)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1560584 13f79535-47bb-0310-9956-ffa450edef68
PIG-3511: Security: Pig temporary directories might have world readable permissions (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1560587 13f79535-47bb-0310-9956-ffa450edef68
PIG-3677: ConfigurationUtil.getLocalFSProperties can return an inconsistent property set (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1560588 13f79535-47bb-0310-9956-ffa450edef68