I'm wondering what we should use instead of portal_skins + customize folder.
How can i provide such TTW override mechanism in a modern way?
i thought plone.resources should the replacement for portal_skins but, it doesn't seem to fulfill the requirements or it is not well documented how to use it in such way.
What we need:
- templates in file system
- overriding them TTW like with the old custom folder
- restricted python is fine here
This should not work only in a theme 
Any hints or ideas?