Guest write access

It would be so usefull to be able to provide friends write access to a shared folder of the gmx file storage, either:
- via a dedicated password (one for read access, one for read & write access)
- via a user-per-user assignment (requiring those friends to create a gmx account).
- In both cases, it would certinly be a "+", as a gmx user, to see in your own file storage the folders shared to you by your friends, in read and write access.