Extract functions: avoid creating joda objects for each row
Remove RemoveSortRule and PushSortPastProjectRule during Drill Logical planning phase.
fix NPE in merging receiver
Add support for non-equijoins in the presence of other equijoins between the same tables.
Specify target traits based on converted RelNode's trait, in stead of empty trait sets, when call planner to get the logical plan.

Add back RemoveSortRule to Logical rulesets.
Fix EXPLAIN plan which was broken in recent change, add test case for EXPLAIN.  Move debug msg in DrillSqlWorker to logger.
AltSort: Replace sort with ExternalSort, Limit + sort with Limit + topN in the generated physical plan.
fix cleanup methods in ExternalSortBatch and TopNBatch.
Bug in ExpressionStringBuilder while parsing timestamp constant.
Add tests for POSTFIX operators added in 097fc00b375b8a171a53e8062d03f06b350ae14e