PIG-3419: Pluggable Execution Engine (achalsoni81 via cheolsoo)


git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1519062 13f79535-47bb-0310-9956-ffa450edef68
PIG-3374: CASE and IN fail when expression includes dereferencing operator (cheolsoo)


git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1519104 13f79535-47bb-0310-9956-ffa450edef68
PIG-3349: Document ToString(Datetime, String) UDF (cheolsoo)


git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1519108 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk