[cairo] Finding minimum distance to a stroke or fill

[Bill Spitzak]

Carl Worth wrote:

> One question we can ask is,
> does anyone have a use case in hand that would require finding the
> nearest point (rather than just the distance)?

This is probably useful for an editor to insert new points into an 
existing path where the user clicks. However it probably also wants to 
know the index of the path segment, and for Beziers it also wants to 
know the t value of this nearest point.