PIG-3464: Mark ExecType and ExecutionEngine interfaces as evolving (cheolsoo)


git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1524461 13f79535-47bb-0310-9956-ffa450edef68
PIG-3466: Race Conditions in InternalDistinctBag during proactive spill (cheolsoo)


git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1524464 13f79535-47bb-0310-9956-ffa450edef68
PIG-3455: Pig 0.11.1 OutOfMemory error (rohini)

git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1524466 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk