did not account for empty generated keys while refactoring
[postgres] support exec_insert with PS + make sure RETURNING works
as it needs some hand-tunning on AR <= 3.2 (AR 4.0 finally got it right)
also with Postgre's JDBC driver we can not use generated keys currently
[postgres] allow nil with last_inserted_id (due disabled generated keys)
better `last_inserted_id` unwrapping on the base adapter level
improve timestamp/time/date values sent to JDBC from prepared stmnts
[sqlite] a saner way of getting last_insert_row_id() via the JDBC API
[sqlite] query-ing last_insert_id after each INSERT stmnt seems redundant
[sqlite] also avoid last_insert_id query after INSERT on AR-2.3
improve nanos handling since `microseconds` returns more than expected
handle DateTime (returned from TimeWithZone.to_time) with PS
re-build jar