Implement negative substring offset
Add UTF-8 support for substring.  Add VARBINARY as a valid type for substring.
s/bin_substr/byte_substr
Sort operator using HyperBatch concept.  Supports single and multikey asc/desc sort.
One comparator function definition.
Add abstract record batch, vector container and vector wrapper.
Various fixes to return to client when query fails.
Work done for optimizing and parallelizing a read from a parquet file.

Data types currently supported INT, LONG, FLOAT, DOUBLE.

ParquetStorageEngine used to break up entire read operation into sub scans that
can be executed independent from one another.