DOMRequest should be dropped #61

Mounir says:

As said during the F2F, now that the Future interface is in the DOM specification [1], it would be great if the usage of DOMRequest was dropped in favour of Futures. Generally speaking, it would be a good rule of thumb to use Futures for any asynchronous operation

[1] http://dom.spec.whatwg.org/#futures

So, DOMRequest should be removed from the spec.

http://lists.w3.org/Archives/Public/public-sysapps/2013Apr/0129.html