Hoverboards for minetest

Description

Add hoverboards to minetest

• Hummer: controls really to review
• I-Wheel: Done
• Scooter: No model yet
• Auto stabilize model: No model yet

It is mostly intended to be used with minetest_game, but other games may be compatible. Not ultra laggy but there is really improvements to be done

Licence

Code under MIT licence terms Artwork under Free Art License

Current state

The logic for hoverboard moves is wrong and should be reworked.