Nabil Freij

@Cadair you can merge when you are happy with it.

Changelog and backport?

Rebased, I think we can merge when things pass

We could vendor that function into extern (assuming its simple to do)?

What about the skiimage one?

I guess it might be if its too complex to bundle in.

Worth a whatsnew?

The docbuild failed on 1 warning, I can't find a doc warning but I can see a setup.py one. I just would have assumed that would have failed on more...

If this is something that can be done easily and without breaking anything, I am all for it.

I can bump the major version.