Installing a module that lists no permissions under a granted id now
forgets the grant, in the process and in grants.json, so the formerly
approved bytes need a new approval. A refused install leaves the grant.
Attaching a plug-in store forgets the grant of an id whose stored module
lists no permissions. A plug-in folder load forgets the process's grant
for such an id and leaves grants.json alone, because the store keeps the
module its grant covers.