DRILL-993: Remove redundant comparison in comparison operator generated by FreeMarker template.
DRILL-772 :  Change comparison operator to use NULL_IF_NULL policy, when inputs are nullable type.
DRILL-1006 : Fix case expression when conditions are expression of nullable types.
DRILL-1020: Fix bug in dynamic allocation
DRILL-1009: Remove 'HBasePStoreProvider' from HBase storage module's drill-module.conf
DRILL-1007: Unify handling of negative values in Decimal28 and Decimal38 data type
DRILL-1023: Fix issue where joins are over estimated causing excess parallelization.  Use correct interfaces for retrieving row counts.
DRILL-1008: Update the way that Windows sqlline.bat composes its classpath
DRILL-953: Handle the case in which /var/log/drill does not exist
DRILL-1022: Increase default min hash table size and allow setting min/max size for hash table.
DRILL-875: Fixes for DRILL-707, DRILL-780, DRILL-835 (Schema change), DRILL-852, DRILL-876, DRILL_877, DRILL-878, DRILL-890
DRILL-748: C++ Client. Support timestamp/date before unix time and handle y2028 problem.
DRILL-870: C++ Client. Support negative interval types.
DRILL-898: C++ Client. Fix decimal data type.
Refactoring - Define function holder and registry interfaces

This change is needed in order to pull out Hive storage/function source code out of
'exec/java-exec' moudle into 'contrib/storage-hive' module. Currently 'exec/java-exec'
depends on 'contrib/storage-hive' (which currently just builds a shaded hive-exec jar).
Ideally 'contrib/storage-hive' should contain the Hive storage/function source code so
that there is a clear separation between core execution engine and Hive storage engine
code.

Note: Interfaces defined for function holder and pluggable function registry may not be
complete and need more discussion to standardize these interfaces.
Code reorg - move hive storage code out of 'exec/java-exec' into 'contrib/storage-hive' module.