DRILL-604: Add schema type to INFORMATION_SCHEMA.SCHEMATA.

Modification for SubSchemaWrapper.
DRILL-635: Fix run-time code generation bug for case expression, when the holder of return type does not have value field.
DRILL-700: Extend AvaticaDrillSqlAccessor to support getDate(), getTime() and getTimestamp()

 + Added accessor methods for getDate(), getTime() and getTimeStamp() in each of the data type's accessor class.
DRILL-718: Return complex types as JSON string.
DRILL-731: Speedup TestConvertFunctions test case
DRILL-749: Zero-fill the Offset Vectors buffer contents
Disabling intermittently failing JsonRecordReader2Test.
DRILL-733: Reduce memory footprint of unit tests
DRILL-750: Use a singleton PooledByteBufAllocatorL instance for all TopLevelAllocator instances
DRILL-707 : Replace ValueAllocator with allocateNewSafe() in SVR. WIP.

remove valueallocator in SVR.

SV for Limit OP.

Selection vector remover. More WIP.

code clean up.

reverse rule change.
DRILL-728: Show SelectionVectorRemover and single mode changes in text plan output.
Zero out RepeatedMap and RepeatedList offset vectors.  Advance var* lastSet when using copy safe.
DRILL-712: Right side of Left join has zero values when should be null
Fix bug in SVR, handling the remaining copy.
Additional comments regarding DRILL-728
Disable failing test
Disabling HBaseTestsSuite, will enable after ValueVector fix.

+ Reduced the memory requirements of the test.
DRILL-384: Move some Fragment initialization work to run() method
Enable sv2 support for project operator.

Currently, this will do copies for all vectors if their is incoming sv2.
Fix minor bugs in ParquetWriter.