MovementTrait
constMovementTrait:Trait<{acceleration:number;deceleration:number;maximumTurnSeconds:number;speed:number;standingShare:number;standTurnRate:number;turnAngle:number;turnInPlace:boolean;turnRate:number; }>
Her movement settings, on each character, so a game tunes its own and every
world keeps its own. spawnCharacter adds the defaults.