Licensing of code in 2D.ts

[mccalluc]

/**
 * The intersection is based on Kevin Lindsey
 * http://www.kevlindev.com/gui/index.htm
 *
 * copyright 2002 Kevin Lindsey
 */

I've looked around at that URL, and haven't found an explicit license. This doesn't need to be resolved immediately, but I think it needs to be more clear before a formal release. Are we using this functionality currently? Is there another library that could provide it, perhaps as a dependency? Is there other unlicensed code in the project?