ignore url query strings in file path

[alancmclean]

URL Query strings are included in the file path causing "file not found" errors. This should workaround that. Nothing fancy, just a split on the first ? encountered in the file path.

[mbostock]

Better would be something like this:

function defaultFile(url) {
  var i = url.indexOf("/", 1) + 1,
      j = url.indexOf("?", i + 1);
  return decodeURIComponent(url.substring(i, j < 0 ? url.length : j));
}

But of course this is still a pretty poor URL parser, but it’s probably okay for something intended to be overridden.

Best would to add some tests. ;)

[alancmclean]

Yep, this is a lot nicer. Will update.
Introducing tests seems like a separate PR maybe? Got a preference for testing?

[mbostock]

That was more a note to myself re. tests. But I’d probably use vows (which is a little long in the tooth but I haven’t bothered to learn a replacement yet) as seen in the smash repo.

[alancmclean]

Updated with your feedback verbatim.