Special thanks to @eladyn for all of their help and suggestions.
* Add all player events to `player_event_handler.rs`
* Move event handler code to `player_event_handler.rs`
* Add session events
* Clean up and de-noise events and event firing
* Added metadata support via a TrackChanged event
* Add `event_handler_example.py`
* Handle invalid track start positions by just starting the track from the beginning
* Add repeat support to `spirc.rs`
* Add `disconnect`, `set_position_ms` and `set_volume` to `spirc.rs`
* Set `PlayStatus` to the correct value when Player is loading to avoid blanking out the controls when `self.play_status` is `LoadingPlay` or `LoadingPause` in `spirc.rs`
* Handle attempts to play local files better by basically ignoring attempts to load them in `handle_remote_update` in `spirc.rs`
* Add an event worker thread that runs async to the main thread(s) but sync to itself to prevent potential data races for event consumers.
* Get rid of (probably harmless) `.unwrap()` in `main.rs`
* Ensure that events are emited in a logical order and at logical times
* Handle invalid and disappearing devices better
* Ignore SpircCommands unless we're active with the exception of ShutDown
Include a systemd.service file to run as a user
This new `systemd.service` file allows running and controlling the service as
an unpriviledged user (generally, as part of a user session).
