I've been working on this off-and-on for a few days without committing
anything 🤨. With this commit, the basic functionality for writing
configuration files from _etcd_ keys is in place. The daemon connects
to _etcd_ on startup, reads all currently-populated keys, and then
enters a watch loop. It gracefully handles being disconnected from
_etcd_ and will reconnect with a backoff timer. In addition to writing
file contents, the daemon can set file permissions and run commands
after changing files.
Dustin