Spinout changes

Title, this changes some Spinout behavior, most notably, spinout is now affected by friction until a lower speed, and always if it's in offroad, as it was before able to go through even glue offroad without losing speed.

(behavior without the change)

The lack of friction also let spinout drag you way too far ahead, making bananas rather useless on straights, but deadly in turns where they sent you far into offroad, or in a pit should there be no offroad, if placed anywhere near a turn.

(behavior without the change)

This is the behavior with the change: