python-fu : close xcf/clear memory

[ChameleonScales]

Ok so I confirm that non inserted layers are kept and I could prevent having any remaining ones before the image gets deleted, so no need to list them (still curious to know if that's possible though).

I however get a segmentation fault and crash when trying to print a non inserted layer after deleting it with pdb.gimp_item_delete. Is this expected or should I make a bug report ?