The tracking reference and other delivery references are not relevant to
duplicated pickings. Overwrite copy to remove carrier_tracking_ref, volume and
number_of_packages.
Add fallback on stock.picking.in and out to use copy method of stock.picking.
For partial delivery, the duplicated picking is the delivered order and
the existing picking is the backorder of the delivery (why so much hate?).
This means we have to switch the delivery info between the backorder and
the delivered picking.
Combo opw 615593 and 618802
Martin Trigaux
f406847613