title: Dynamically added form fields are removed in form.cleaned_data
body: <p>I put some client-side Javascript in my template that allows a user to dynamically add fields to a form.  My problem is that these fields are cleaned in <code>form.cleaned_data</code>, so I can't access them that way.</p>
  
  <p>All the fields are accessible in <code>request.POST</code>, so I could just solve this problem with that, but I want to do this the "right way" and I think that the solution lies somewhere in using django forms rather than reading the request directly.</p>
  
  <p>I tried overriding <code>form.clean()</code>, but it seems like the data is already gone by the time it gets there.</p>
  
  <p>Other details: I am naming these fields <code>fieldname_x</code>, where <code>x</code> is a number.  In <code>request.POST</code>, <code>request.POST['fieldname']</code> is a list of a all the values, but <code>form.cleaned_data</code> contains only the last value of each list.</p>