The point is that fibrous.js automatically wraps the standard fakes.js yet it does catch throwAsync

Also, all the other fake APIs except `fakes.js` (and fakes-ctx.js for a [different reason](http://spion.github.io/posts/closures-are-unavoidable-in-node.html)) are wrappers around the original callback-based `fakes.js` created using the standard wrapping facility of the library in use.