title: FormData and checkboxes
body: <p>Currently when creating a <code>FormData</code> object, a checked checkbox is added with a value of "on", and an unchecked checkbox is not passed at all.</p>
  
  <p>Do I have to hack in some hidden inputs to properly set checkboxes, or is there some customization I can do with FormData, or pre processing? </p>
  
  <p>I would prefer a checked checkbox to be 1 and an unchecked to be 0. I can already do this myself (ie ugly hack), but I don't see any native way with FormData.</p>