Implementing union
Almost fixed all tests so they pass in Postgres
Using a more standard filed type to temporarily avoid building schema
creation features :P
Adding a new method to get any clause from the query
Refactoring distinct so it is stored in the _parts array
This commit makes all postgres tests pass, but will break the other
drivers for the time being, next step: Driver builder functions
Implementing a basic Dialects system and a way for them to translate a
query object to the target driver
A bit of refactoring for clarity... Did I mention that all tests pass
for all implemented drivers? :)