Add Resource.get_diff_class() - fixes #745
Add Resource.get_diff_class() - fixes #745

django-import-export/django-import-export,daniell/django-import-export,jnns/django-import-export,django-import-export/django-import-export,jnns/django-import-export,django-import-export/django-import-export,jnns/django-import-export,bmihelac/django-import-export,daniell/django-import-export,daniell/django-import-export,bmihelac/django-import-export,jnns/django-import-export,bmihelac/django-import-export,django-import-export/django-import-export,bmihelac/django-import-export,daniell/django-import-export