support web-workers XMLHttpRequest

[hankhero]

for a web-worker, window is unavailable butXMLHttpRequest is available on the global 'self' object

[canastro]

This would be really useful!

[tschaub]

How about this:

if (typeof XMLHttpRequest !== 'undefined') {
    return XMLHttpRequest;
}

And then remove the second check for window.XMLHttpRequest below.

[tschaub]

Agreed this would be useful. For others looking to work around the window checking, you can add this hack to whatever module requires http:

self.window = self;

And with this, window.XMLHttpRequest will be defined.