Skew tweening fix

[ericente]

Makes skew tweening always go the short way. Previously a skew tween from 180° to -170° would traverse 350° when the default behavior in Animate would be a tween of 10°.

[ericente]

Just realized I could probably written this as:

function lerpSkew(start: number, end: number, t: number): number
{
    let value = lerpRotation(start, end, t);
    if (value > PI) return value - TWO_PI;
    if (value < -PI) return value + TWO_PI;

    return value;
}

Not sure if you have a preference...

[andrewstart]

This works, as we could change rotation lerping in the future without messing up skew.