DRILL-643: Fix ByteBuf allocation in o.a.d.exec.vector.ValueHolderHelper.getVarCharHolder()
DRILL-644: Fix char length and position calculation for UTF-8 strings in StringFunctionUtil
DRILL-645: Correct string encodings in code template
DRILL-381: Implement SYSTEM and SESSION options.
DRILL-219: Math Trigonometric functions
DRILL-627: Fix memory leaks in hash join and hash aggregate
DRILL-640: Fix memory leak in limit operator
DRILL-577: Two way implicit casts
DRILL-438: Add support for Views (CREATE, DROP and select)
Fix DRILL-576: Cumulative changes for Drill costing, new plans for joins and aggregations, including distributions.
Rebase on master branch and integrate costing changes with the GroupScan's row count.
Revert the plus and minus logic of costs to do the add and subtract of the row counts instead of taking the Max.
Add cleanup() methods to MergeJoinBatch and HashJoinBatch.
Don't match hash aggr rule if number of grouping cols is 0. Fix build after rebase.
Revert "DRILL-627: Fix memory leaks in hash join and hash aggregate"

This reverts commit bffd19ecf3ea5d23bbbe6a8ff5936af32be5cf0d.