fixes bug 1067548 - API testdrive binary data and failure after success

@rhelmer r?

Now it looks like this instead:
![screenshot 2014-09-15 14 49 39](https://cloud.githubusercontent.com/assets/26739/4279520/3e85e70a-3d22-11e4-9d36-99e5800473e8.png)

I was cheeky and extended the functionality slightly by adding the "Size: XXX.X Kb" output too. I think this helps to be able to tell what was returned. 
I don't think there's any harm, but ```click()``` is just a shortcut for ```on('click')``` isn't it? http://api.jquery.com/on/#additional-notes

In any case, I prefer these kinds of changes to be in their own PR so they don't derail more important changes - not that I am not guilty of doing this to. In any case I think this change is fine.