Support conventions on a predefined set of types

So currently the convention works by scanning assembly for types.

This doesn't work well in every case.

I just hit a scenario where I have a type with properties, and I want a convention that works off of generic argument of property types of that type.

Basically it looks like this

`public class Cache
{
   public CacheData<Foo> Foos { get; set; }
   public CacheData<Bar> Bars { get; set; }
}`
