Normalized empty results and added tests for these cases.
Confirmed that result is null on error
query() now returns [] when no rows found and on error. queryOne now returns null on now rows found or error. Added dependency on dateformat and simplified dateHelper a bit. Wrote a simple test for dateHelper. Bumped version.
Merge pull request #5 from Mindflash/emptyResults

Normalized empty results and added tests for these cases.