title: Mapping a different field OneToOneField in a ModelForm
body: <p>I have two django models related with a OneToOneField. I'll show the relevant fields:</p>
  
  <pre><code>class User(AbstractBaseUser, PermissionsMixin):
      email = models.EmailField(unique=True, db_index=True)
  </code></pre>
  
  <p>And</p>
  
  <pre><code>class PasswordRecovery(models.Model):
      user = models.OneToOneField(User, primary_key=True)
      token = models.CharField(default=utils.make_token)
      password = models.CharField(max_length=128)
  </code></pre>
  
  <p>Then I have a form for the PasswordRecovery model</p>
  
  <pre><code>class PasswordRecoveryForm(forms.ModelForm):
      password_check = forms.CharField(max_length=128)
      class Meta:
          model = PasswordRecovery
          fields = ('user', 'password', 'password_check')
  </code></pre>
  
  <p>A few details are omitted here. Tell me if you think they are relevant.</p>
  
  <p>The problem is that the user field shows as a 'select' element and I would like it to be an email field. Instead of being able to chose a user from a lista I want it instead to required the email to be typed.</p>
  
  <p>How can I do this?</p>
  
  <p>Thanks in advance</p>