ActivityPubPlugin:
- update grab_notice_from_url to make online grab optional
- subscribe events of user and profile deletion
- bump minor version number
Activitypub_inbox_handler:
- separate handle_delete for delete-note and delete-person
Activitypub_postman:
- add delete-person logic
Activitypub_delete:
- update validation method to check for the "Person" type
- update to_array method to target the activity
