app term should become unmapped if public composite term it was mapped to is changed back to private

[TravisWalterLBNL]

If user1 creates a composite term and makes it public, then user2 maps an application term to that composite term, then user1 changes the composite term from public back to private, user2's application should become unmapped (since they should no longer have access to user1's private composite term). Currently, user2's application term stays mapped to user1's composite term even after user1 make the composite term private.