title: Django ModelTranslation local fields clash with parent´s model fields
body: <p>I´m developing a website with Mezzanine and I´m having problem trying to configure modelTranslation plugin for it.I´m using Django 1.8.9 and Mezzanine 4.0.1, django_modeltranslation 0.11.</p>
  
  <p>I have a model class GenericContent with some fields :</p>
  
  <pre><code>class GenericContent(models.Model):
      image_footer = RichTextField(blank=True)
      video_footer = RichTextField(blank=True)
      summary = RichTextField(blank=True)
  
  class BasicContent(Page, RichText, GenericContent):
      pass
  </code></pre>
  
  <p>In the translation.py file for the basicContent app, we have the following modelTranslation translation definitions :</p>
  
  <pre><code>class TranslatedGenericContent(TranslationOptions):
      fields = ('summary',
                'image_footer',
                'video_footer',)
  
  class TranslatedBasicContent(TranslationOptions):
      pass
  
  translator.register(GenericContent, TranslatedGenericContent)
  translator.register(BasicContent, TranslatedBasicContent)
  </code></pre>
  
  <p>With this configuration, it doesn´t show errors, but the basicContent doesn´t get translated(the inherited fields from genericContent are registered for translation, but in basicContent they don´t get translated, nor any other fields from the parent classes[Page and RichText], which are Mezzanine included classes and registered for translation).</p>
  
  <p>If I try to modify the translation.py file :</p>
  
  <pre><code>class TranslatedGenericContent(TranslationOptions):
      fields = ('summary',
                'image_footer',
                'video_footer',)
  
  translator.register(GenericContent, TranslatedGenericContent)
  translator.register(BasicContent, TranslatedGenericContent)
  </code></pre>
  
  <p>This other configuration gives and error when trying to run <strong>python manage.py sync_translation_fields</strong></p>
  
  <pre><code>basicContent.BasicContent.image_footer_en: (models.E006) The field 'image_footer_en' clashes with the field 'image_footer_en' from model 'basicModels.genericcontent'.
  basicContent.BasicContent.image_footer_es: (models.E006) The field 'image_footer_es' clashes with the field 'image_footer_es' from model 'basicModels.genericcontent'.
  basicContent.BasicContent.summary_en: (models.E006) The field 'summary_en' clashes with the field 'summary_en' from model 'basicModels.genericcontent'.
  basicContent.BasicContent.summary_es: (models.E006) The field 'summary_es' clashes with the field 'summary_es' from model 'basicModels.genericcontent'.
  basicContent.BasicContent.video_footer_en: (models.E006) The field 'video_footer_en' clashes with the field 'video_footer_en' from model 'basicModels.genericcontent'.
  basicContent.BasicContent.video_footer_es: (models.E006) The field 'video_footer_es' clashes with the field 'video_footer_es' from model 'basicModels.genericcontent'.
  </code></pre>
  
  <p>Have you ever experienced this problem? I´m looking into a fix for this. Any help would be appreciated!</p>