title: Personalize form field name (with formset)
body: <p>I would like personalize the field name render like with <strong>auto_id</strong>. Some code:</p>
  
  <pre><code>&gt;&gt;&gt; from django import forms
  &gt;&gt;&gt; from django.forms.formsets import formset_factory
  &gt;&gt;&gt; class MyForm(forms.Form):
  ...   name = forms.CharField()
  ... 
  &gt;&gt;&gt; myform_formset = formset_factory(MyForm)
  &gt;&gt;&gt; print myform_formset(auto_id='my_form_%s')
  
  &lt;input id="my_form_form-TOTAL_FORMS" name="form-TOTAL_FORMS" [...]
  &lt;tr&gt;&lt;th&gt;&lt;label for="my_form_form-0-name"&gt;Name:&lt;/label&gt;&lt;/th&gt;&lt;td&gt;
  &lt;input id="my_form_form-0-name" name="form-0-name" type="text" /&gt;&lt;/td&gt;&lt;/tr&gt;
  </code></pre>
  
  <p>Ids are personalizeds: id=" <strong>my_form_</strong> form-0-name". Actually, field names are render like this: name="form-0-name". I would like render them like name=" <strong>my_form_</strong> form-0-name".</p>
  
  <p>Why i need it ? I've two differents formset in my form, so i've multiple field with name "form-0-name" and it's not good for POST data.</p>