Add failing tests for Issue #174 (TDD)
Improve quality of error message
Adopt ValueError as the desired Python exception and make more consistent with other negative tests
make diff_pylint_report tweaks
Fix Issue #174 - ktable.get(wrong_length_string) gives core dump
Update ChangeLog
Modify some user-visible output strings
Merge pull request #585 from Echelon9/fix/get-wrong_length_string

Fix table.get("wrong_length_string") gives core dump
clarify checklist
update URL to dev docs
Merge pull request #584 from ged-lab/doc/pylint-diff

clarify checklist & update dev docs URL