DRILL-607, DRILL-593: Fix casting from Int, BigInt to Decimal28, Decimal38
DRILL-608: Fix casting to decimal data types with difference scales.
DRILL-558: Remove workaround in OptiqScanner for skipping "metadata" subschema.
Remove the *.orig files lying in the repo.
DRILL-623: Unable to run query containing quoted schema name
DRILL-646: Broadcast-inner plans for Hash Join and Merge Join.

 - Consolidated planning methods in base class.
 - Add option to enable/disable broadcast join. Default is disabled for now.