Refind-btrfs

This release fixes breaking changes which were introduced upstream ([watchdog](https://github.com/gorakhargosh/watchdog) library). Related issues are #42 and 43.
PyPI users should upgrade their watchdog installation with: `pip install watchdog --upgrade`

This release fixes the following [bug](https://github.com/Venom1991/refind-btrfs/issues/41).

- fixed [this](https://github.com/Venom1991/refind-btrfs/issues/38) bug
- implemented [this](https://github.com/Venom1991/refind-btrfs/issues/35) feature (new config option [description](https://github.com/Venom1991/refind-btrfs/blob/master/src/refind_btrfs/data/refind-btrfs.conf-sample#L132))
- regenerated ANTLR code