Locator should only accept types that are Findable

[alechenninger]

But this means some things might need to happen with regard to ParentContexts, since right now they, by default, can just find plain old Contexts, which are not Findable.

Could...

• Make Context extend Findable. I would not be surprised if everything that implemented Context already did implement Findable.
• Make ParentContexts find T extends Context & Findable, in which case a FindableElementContext type would have to also be derived.

I think the first option is best.