bump version for flatpak

flatpak: add developer and launchable to metainfo

flatpak: remove `/lib/debug` from cleanup

- Use `gsettings` instead of `dconf` to disable mouse on wayland,

- Use `PIL.Image.LANCZOS` instead of `.ANTIALIAS` (which is deprecated),
- Bump version to v1.2.7

Add nix instructions in README

Remove requirement for xinput on Wayland-based compositors

Add support for `--fullscreen`

Added hotfix for Arch/Manjaro based distros + Verify pillow version

Arch/Manjaro problem was that it doesn't set /org/gnome/desktop/peripherals/touchpad/send-events to any value by default. I assume it's "enabled" if it's empty now

Work with old `pillow` versions

Merge branch 'master' of github.com:Wazzaps/fingerpaint