Bum

- Added `--port`
- Added `--server`

- pypi: Fix install error.
- brainz: Send correct `bum` version.

- Removed a `sleep` that is no longer needed.

- `bum` now connects to `mpd`/`mopidy` directly.
- `bum` waits for `mpd` to send `player` events.
- `bum` no longer requires any user configuration.
- It just works out of the box now.
- No more `SIGUSR1`.
- Removed `mpc` dependency.
- Added `python-mpd2` dependency.
- All dependencies are now installed with `pip`.
- Fixed hang when next song is mashed.

- Fixed `mpv` error on older versions.
- Cleaned up code.

- Don't send `%date%` to `musicbrainz` as more often than not `spotify` has the wrong tags.