plastic saving version of parametric round box

a two small fixes to make the box weight bit less, while still being stackable.

internal walls are made 1/2 of wall thickness and top lid base thicknes is 1mm .

todo - i usually emboss some nice victorian pattern on top of box with blender , but this
could be as well done in openscad.

also external box walls are still too thick but i had no quick idea how to make them thinner while still retaining some kind of reinforcement.