Document table columns better

[rod-glover]

Column names alone are frequently not sufficient to understand what they are for. Look into whether that documentation can be part of the SQLAlchemy column definition so that it propagates into the database proper as well.

[Nospamas]

A thought, if nothing else then adding the documentation at the ORM should at least let people get column descriptions during usage on intellisense. Can docstrings be used for that sort of thing?