Separate registry for manager shouldn't be needed any longer -- the main registry caches options for all seen models.
Now it might be possible to optimize the manager by precomputing or caching ``fields_to_translatable_models`` on translation options (instances).
Adapt management commands and a debug message (by using ``get_registered_models`` rather than directly ``registry``).
Adapt admin to new translation options, allowing it to manage translation fields inherited from concrete supermodels.
``TranslationOptions.localized_fieldnames_rev`` is no longer available, but should be replaceable by field.translated_field (may be readded as a ``TranslationOptions`` method if it's useful for something).
Test registration and translation fields inheritance with a more complex model hierarchy (inspired by Mezzanine).
Small cleanup in ``FieldsAggregationMetaClass``. The manual inheritance syntax is left mostly for backwards compatibility.