title: Django: ForeignKey to_field and db_column doesn't seem to work
body: <p>I'm trying to get the field value for <code>select</code> widget using <code>to_field</code> or <code>db_column</code> arguments, but they doesn't seem to work.</p>
  
  <p>Here is the model:</p>
  
  <pre>
  <code>
  class Employer(models.Model):
      e_name     = models.CharField(
                                    max_length = 40, 
                                    verbose_name = 'Name')
  
      e_lastname = models.CharField(
                                    max_length = 40, 
                                    verbose_name = 'Lastname')
  
      e_position = models.ForeignKey(
                                     to = Position,  
                                     db_field = 'p_name', # this is the thing I want to display as a select widget option
                                     verbose_name = 'Position')
  </code>
  </pre>
  
  <p>Instead I've only the models' names in select widget, also <code>db_column</code> make reference to the <code>Employer</code> model, but <code>Position</code> reference.</p>
  
  <p>What is going wrong or new features I don't know about?</p>
  
  <p>Sultan</p>