title: Exporting using django-import-export and showing verbose names of related objects
body: <p>I was having a look at the following library - django-import-export.
  However, I am having issues with exporting with friendly/verbose column names for related objects.</p>
  
  <p>Related link: <a href="https://github.com/django-import-export/django-import-export/issues/52" rel="nofollow noreferrer">https://github.com/django-import-export/django-import-export/issues/52</a></p>
  
  <pre><code>class HumanModelResource(resources.ModelResource):
  def get_export_headers(self):
      headers = []
      for field in self.get_fields():
          model_fields = self.Meta.model._meta.get_fields()
          header = next((x.verbose_name for x in model_fields if x.name == field.column_name), field.column_name)
          headers.append(header)
      return headers
  
  class Meta:
      model = Human
      fields = ("name", "pet__name")
  
  class HumanAdmin(ExportMixin, admin.ModelAdmin):
      resource_class = HumanModelResource
      list_display = ("name", "pet")
  
  class Human(models.Model):
      name = models.CharField(max_length=255, verbose_name="Name")
      pet = models.ForeignKey(Pet)
  
  class Pet(models.Model):
      name = models.CharField(max_length=255, verbose_name="Pet Name")
  </code></pre>
  
  <p>Exporting will show "Name" for the human but the pet name will show up as "pet__name".</p>
  
  <p>I'm not sure how to approach overriding the get_export_headers method to display the related objects verbose name.</p>
  
  <p>I am currently using:
  - Python 2.7
  - Django 1.11</p>