Pluggable Data Layer

This release marks a rewrite of how the ORM interacts with the data layer. Previous versions of the ORM have assumed a database connection using PDO through the Database/Connection object.

By change the Connection object to now be effectively a Dependancy Injection Container, the Core ORM functionality no longer has concrete functionality for accessing data, instead relying on the Connection object to supply both a DataAccess and Schema object. This allows for us to provide alternative Connection objects that back onto different tech stacks, including "Fake"d stacks allowing for unit testing without hard DB dependancies.