We should add a way to easily encapsulate conventions, similar to how a user can inherit from EntityTypeConfiguration<T>.
Design meeting notes for this: https://entityframework.codeplex.com/wikipage?title=Design%20Meeting%20Notes%20-%20March%2013%2c%202013
Design meeting notes for this: https://entityframework.codeplex.com/wikipage?title=Design%20Meeting%20Notes%20-%20March%2013%2c%202013