DRILL-263: PartitionSender not setting opposite minor fragment id correctly
DRILL-242: fix negative hash values, sort order POP case and sending of empty batches with no schema
DRILL-264: MappingSets should not be static
DRILL-230: Build a sampling range partitioner
DRILL-230: Addressing comments in code review, abstract out references to HazelCache and add comments
Add rb/jira review tool
DRILL-45: Implement builders for Scan, Sort, LogicalPlan and PlanProperties.
rebase DRILL-45 to current master
implement SV4 support for filter
DRILL-193: add missing copyright headers
Add Apache License to review tool so RAT doesn't break.