title: Django: "Can't convert 'Name' object to str implicitly" on saving object
body: <p>In Django admin, I have created a Name object with name: "United Kingdom". I then create a Nation object with the Name object I've just created, and a path to a flag image. </p>
  
  <p>On saving the entry, I get:</p>
  
  <h2>TypeError at /admin/display/nation/add/</h2>
  
  <pre><code>Can't convert 'Name' object to str implicitly
  Request Method: POST
  Request URL:    http://127.0.0.1:8000/admin/display/nation/add/
  Django Version: 1.6.2
  Exception Type: TypeError
  Exception Value:    Can't convert 'Name' object to str implicitly
  Exception Location: \models.py in __unicode__, line 24
  </code></pre>
  
  <h2>Relevant section of models.py</h2>
  
  <pre><code>class Name(models.Model):
      def __unicode__(self):
          return 'Name: ' + self.name
      id = models.AutoField(primary_key=True)
      name = models.CharField(max_length=32)
      class Meta:
          db_table = 'name'
  
  class Nation(models.Model):
      def __unicode__(self):
          return 'Nation: ' + self.name
      id = models.AutoField(primary_key=True)
      name = models.ForeignKey(Name)
      flag_path = models.CharField(max_length=64)
      class Meta:
          db_table = 'nation'
  </code></pre>
  
  <p>From the error message I understand that <code>return 'Name: ' + self.name</code> needs to get a string back to append to 'Name: ', but how would I amend my models.py to allow that? </p>