Support relational databases

[groenroos]

Currently the codebase is largely written around document based database systems (i.e. MongoDB), where a lot of the restrictions of conventional relational databases (i.e. MySQL) do not exist.

For instance, MongoDB will automatically create databases and tables that do not exist simply when they are first referenced. Records can include new keys without having to separately modify the collection to add the column first. These freedoms do not exist in most relational database systems.

This sort of heavy lifting can still be abstracted away from the end user of the framework however, if the db/Interface.js and storage.js are adapted to also call separate just-in-case methods for adding databases, tables and columns wherever necessary to make the magic work with relational databases too.