This module provides different configuration option to manage packagings
on sale orders.

The creation/update of sale order line will be blocked (by constraints)
if the data on the sale.order.line does not fit with the configuration
of the product's packagings.

It's also possible to force the quantity to sell during
creation/modification of the sale order line if the "Force sale
quantity" is ticked on the packaging and the "Sell only by packaging" is
ticked on product.

For example, if your packaging is set to sell by 5 units and the
employee fill the quantity with 3, the quantity will be automatically
replaced by 5 (it always rounds up).
