External Tox improvement

Hi there,

I started working with external tox files as a way to make reusable components.
Now there are two things that bug me:

Since I don’t want my parameters to reset, when I reload the tox file, I have to load the tox somewhere in my project and then make a clone of it.
Then I have to manually put all the extensions that the tox had, in the Extensions tab of the clone, otherwise they won’t work.

This works, but seams like a bit of unnecessary work and overhead.
It would be nice, if we could just load a tox without making a clone and manually put in the extensions each time.

Cheers, David