bezierEditor / bezierHandle elements

[TangentFoxy]

Basic idea is a master element (NOT parented) that holds references and draws the curve, and 4 handle objects created that reference what they each need to to modify the curve.

Probably should be part of an expansion to the library for editor tools instead of part of the main suite? Or no?

[TangentFoxy]

The main thing wrong I did in my initial implementation of this for TruckGame is that the data doesn't get updated when the curve is updated, and the curve doesn't update if the data is changed.