Transfer data to SQLite

[NDevox]

KEYS and SPECIALS in particular could do with this.

Should be more manipulable and stable. If we want a Python interface afterwards, views would be safer than handling the actual files.

Need to check safety and how files are stored - as well as dependencies.

[NDevox]

This is now in progress.

I'm going to use sqlalchemy to connect everything up and build the database models.

Started with transactions and accounts. Will get to keys and specials later. Scrapping date objects and need to look into transaction types and bank types - these will be important for how things work in the future.