Removed daemons and updated to work with the latest DatTCP

These are the rest of the changes to go along with adding the CLI. This removes the usage of Daemons and the dependency. I used the process daemonization from puma and it's working as expected. This also updates the `Manager` and `Server` to use DatTCP's new API. Finally, this includes some cleanups and some test suite improvements (switched to using threads instead of forking for the `request_handling` tests, minor speed boost).

All of this is to prep for supporting "hot restarts" and to, in general, add more control over Sanford's server processes. This temporarily has disabled "restarting" as I will be implementing this as a "hot restart" shortly.