DRILL-385: Implement Top-N sort operator
DRILL-386: Implement External Sort operator
DRILL-465: submit_plan does not parse query strings correctly from shell
DRILL-433: Enhance QuerySubmitter to accept custom column width to be used while printing results.
DRILL-464: Fix for RepeatedValueVectors not loading correctly
DRILL-458: Use GenericAccessor for accessing RepeatedTypes in jdbc
DRILL-88: Implement HBase Storage Plugin
DRILL-467: support multiple "and" join conditions in merge join operator.

DRILL-467: Support multiple "and" join conditions in merge join operator.
Update AggregateChecker to add errors to ErrorCollector instead of throwing Exceptions
1. Tests pending
DRILL-443: Fix potential memory leaks inside HashAggregation and HashTable.
Fix Drill-487. Setup mappings appropriately for compare functions. Throw exception instead of assert when no join conditions are present. Enable PushFilterPastJoinRule .
WIP: Adding window op