Resolve InvalidStateError in Internet Explorer when running on localhost

This resolves #1 and a trailing comma issue that would also affect IE.

See also the XMLHttpRequest spec: http://xhr.spec.whatwg.org/#the-withcredentials-attribute

I am not sure which minifier you are using, so you can either minify after merging this request, or I can perform minification if you can provider details on how you prefer the file to be minified.