Ability to select a folder

[andjsch]

Currently, there is no way to select a folder for looping over a directory. I know, you could work around that by choosing any file in that directory and use its path, but selecting a directory directly would be less confusing to the user.

I think it could be a nice addition to the assets fieldtype, to allow selecting directories (additionally or only). This would result (depending on whether you can additionally select or only select a folder) in a new button like this:

What do you think?