Split WorldFolder into base class and factory. Previously, it used __new__ to combine the two, but this required parameters in __new__, which apparently is deprecated.
Split WorldFolder into base class and factory.
Previously, it used __new__ to combine the two, but this required parameters in __new__, which apparently is deprecated.

macfreek/NBT,fwaggle/NBT,cburschka/NBT,twoolie/NBT,devmario/NBT