title: How to change Django Admin Custom list field label
body: <p>How to change in_stock verbose_name ?</p>
  
  <p>Models.py</p>
  
  <pre>class Book(models.Model):
   name = models.CharField(u"Нэр", max_length = 200)
  
   @property
   def in_stock(self):
    return self.stocks.count()
  </pre>
  
  <p>Im Admin.py</p>
  
  <pre>class BookAdmin(admin.ModelAdmin):
   list_display  = ('name', 'in_stock')
   search_fields = ('name', )
  </pre>