Commented Feature: Improve mechanism to retrieve db schema info [415]

Providers are currently required to do some complex things in order to provide schema information about a database. The goal of this work is to simplify the way provider writers implement this functionality while minimizing the disruption to existing providers.
Comments: Added a prototype to my personal fork. Clone URL: https://git01.codeplex.com/forks/bricelambson/entityframework Branch: schema