Ported Print::bounding_box(), Print::total_bounding_box(), Print::skirt_flow(), Print:skirt_first_layer_height() to XS
Consider extrusion width in Print::total_bounding_box()
Bugfix: objects were not aligned to Z = 0 before exporting STL from plater. #2393
Removed two useless methods in Print
Keep model objects aligned to Z = 0 in plater