Log Message:
supertux: Update to 0.6.3

Changelog:
SuperTux 0.6.3 (2021-12-22)
---------------------------
The SuperTux team is excited to announce the release of SuperTux 0.6.3 after \ 
approximately 1.5 years of development.  This release introduces many new \ 
features; perhaps the most new features in a long time!

Some of the most significant changes include:
- WASM compilation! SuperTux nightlies can now be played directly in the browser \ 
(thanks to Semphris)
- Added swimming (thanks to Daniel and Zwatotem)
- Added walljumping (thanks to Daniel)
- Autotiles (thanks to Semphris)
- Updated animations (thanks to Alzter, Daniel and RustyBox)
- Refreshed many contrib worldmaps (thanks to Servalot)
- Many updates to paths, with easing, bezier curves, path sharing between \ 
objects, and more (thanks to Semphris)
- Remade the crystal tileset (thanks to Alzter and RustyBox)
- Many new snow tiles (thanks to Daniel)
- Many new objects, like the sideways bumper and falling blocks (thanks to Daniel)
- Custom particles (thanks to Semphris)
- A new rublight object (thanks to HybridDog)
- Official binaries for FreeBSD, Linux 32-bit and Ubuntu Touch (thanks to Semphris)
- Added in-game progress statistics (thanks to Semphris)
- New color picker based on OKLab (thanks to HybridDog)
- Add-on creator, to easily create add-on packages with your world (thanks to \ 
Semphris)
- Rework of the Revenge in Redmond worldmap (thanks to RustyBox)
- Added timeshift ambience in the worldmap (thanks to Semphris)
- Skippable cutscenes (thanks to Semphris)
- Editor auto-saves at regular intervals (thanks to Semphris)
- Optional integration with Discord (thanks to Semphris)
- Updated translations, of course (thanks to translators)

And these are just the most significant changes; there are plenty of other small \ 
features and bugfixes for you all to explore :)