issue #43: fixed bug with invalid Hibernate table references
issue #43: added support for aggregation with group by to Hibernate Shards
issue #43: added tests for aggregate functions with group by
issue #43: added support for arbitrary selections including mathematical operations (SQL projections) to Hibernate Shards and some tests
issue #43: added support for grouping on SQL selections (SQL projections) to the code of Hibernate Shards and a relevant test
issue #43: sharded getFilteredFrequencyValuesForNumericColumn for charts view