[DustyPorViva]

I believe it was to help playerworlds keep their images organized, but was never used properly. If I remember rightly, it creates a folder for each file that has an underscore it in, making whatever is before the underscore a directory. IE: dusty_tileset.png becomes images/dusty/dusty_tileset.png
No way to turn it off though. Instead of having a folder full of thousands of disorganized images, we get that plus a crapload of pointless folders.