[V157,V158,V160] Track Editor and other improvements

Enhanced Track Editors to allow rapid switching between Advanced and Simple.

On screen clone button in Advanced Track Editor.

Offscreen Distance Indicator for:

Stabilization Indicator on top right corner, during race. (see third video above)

Mac Steam 157, Lin Steam 158, Win Steam 160

Build and release context

Steam update times within 24 hours of this post. Matching dates do not confirm which build it describes.