Return None on error for parsing functions.  These will be converted to default values upon __init__.
Add add_rows utility, to handle common sqlalchemy add_all exceptions with logging.
Docs.
Misc. comments.
Use logging in add_all function.
Define flat file parsing functions that return None following exception.
Replace info['parse'] functions with the new ones, which return None upon exception.
Add more robust column parsing functions, which return None on ValueError.
Add custom __eq__ to PiscesMeta, which requires equality of all primary key values.
Add Sphinx documentation site to docs.