* Recheck device lists when join/leave events come in
* Add PerformDeviceDeletion
* Notify clients when devices are deleted
* Unbreak things
* Remove debug logging
* Make userapi responsible for checking access tokens
There's still plenty of dependencies on account/device DBs, but this
is a start. This is a breaking change as it adds a required config
value `listen.user_api`.
* Cleanup
* Review comments and test fix