[Feature] Create sub folders structure

[ghost]

Allow the option to create the sub folders tree as the group tree in the document.

[Zacchino]

I tested this new feature #86 and it works flawlessly.
Thank you @apauriche !

[skjorn]

Thanks for the contribution! I used it as a basis, but it was easier to implement my own solution. Still, it's very similar to what you did. I didn't like the way it merged files into existing folders, though. So I changed it to rename top folders instead. Also, it should be a bit faster, since I use already collected parent groups. Feel free to download the latest version and modify it to your liking.