Added a way to get types of columns (Not implemented for postgres yet, and I'll probably expand this to return more information such as default values etc to allow for added introspection)
Cleanup
Made predicates aware of the query they are generating for, this allows for more optimizations
Added SELECT DISTINCT
Made unions handle sorting properly
SELECT table.* now also returns model objects
Made NSExpression capable of adding tokens to a query
made BEGINSWITH smarter, it now makes use of indices when possible
Fixed test compile error