* Move more tasks to tootctl

- tootctl feeds build
- tootctl feeds clear
- tootctl accounts refresh

Clean up exit codes and help messages

* Move user modifying to tootctl

* Improve user modification through CLI, rename commands

add -> create
mod -> modify
del -> delete

To remove ambiguity

* Fix code style issues

* Fix not being able to unset admin/mod role

* CLI interface for creating/deleting local users

- tootctl accounts add USERNAME
- tootctl accounts del USERNAME

* Add CLI interface for culling remote users that no longer exist

- tootctl accounts cull

* If an Update is signed with known key, skip re-following procedure

Because it means the remote actor did *not* lose their database

* Add CLI method for rotating keys

    bin/tootctl accounts rotate [USERNAME]

Generates a new RSA key per account and sends out an Update activity
signed with the old key.

* Key rotation: Space out Update fan-outs every 5 minutes per 1000 accounts

* Skip suspended accounts in key rotation