Person Type screen
A user should be able to re-use person types per product.
Currently, as things are, users will keep creating new person types for each product
To address this, we need to create a separate screen for browsing all post types of type "person type".
Also where it currently says
Add Person Type we will need two buttons, one for creating and one for linking to existing person type.
This behaviour is seen in some of the other extensions as a feature. E.g. in the product data metabox, you click Remove but it's not actually removed, it's unlinked from that product, but there is a separate screen for that post type (e.g. person types) where you can actually delete it for real.
The behaviour is similar to that of resources