Added jQuery approach to enabled local HTTP requests with JavaScript

Browsers usually return HTTP status 0 for requests using a local protocol like file, app...
For local development it's nice to use simulated HTTP status 200 or 404 if responseText ist available or not. I created a pull request month ago but it failed with the cpp target (which I don't touch at all). So hopefully this will make in into Haxe 3.1.4.