Regions class is useful for people not using feincms3 too. Since the regions module does not use any of the feincms3's modules, and offers functionalities directly linked and relevant to django-content-editor, it makes sense to move it there. It would also reduce dependencies when no other feincms3 functionalities are used.

This implies that TemplatePluginRenderer.plugins() method to be moved to PluginRenderer. Also, PluginRenderer is initialized with Model registered which causes troubles when trying to pass down plugin_renderers' plugins as:

contents = contents_for_item(page, page_renderer._renderers.keys())

(this provides an error: type object 'Model' has no attribute 'get_queryset', in contents.py in contents_for_items, line 70). This is solved by removing Model from renderer's plugins.