Add schema for cma_case doctype format
Strip the details key from doctype properties

The details key contains information useful for other applications but
not intended for elasticsearch. There will be future work to expose this
information in a useful way.
Make delete action handle a _type parameter

Makes Index#delete take type and id instead of just a link.

This allows us to delete a document with a type other than edition,
without having to add special cases to the `link_to_type_and_id` method.