Extensive refactor, quality of life enhancements

* Added ability to reload config, agreement, news, and user accounts without restarting the server by sending SIGHUP to the running process
* Added ability to use modern unix or windows line breaks in Agreement.txt and MessageBoard.txt instead of classic MacOS `\r` breaks.
* Extensive refactor towards swappable backends for the active server state
* Extensive refactored towards making the hotline package generic and re-usable for alternate server implemenations
* Fix bug where users whose accounts have been deleted would not be disconnected