Price recalculation in sales orders

This module adds two buttons to the sales order form, placed next to the status field at the top of the order. They are only visible while the order is in draft or sent state, so they cannot be used on confirmed orders.

• "Recalculate prices": applies the current pricelist to the order lines. This is useful after changing the pricelist on the order, or after duplicating an order, when you want the prices to be refreshed.
• "Reset descriptions": erases custom descriptions written on the order lines and puts back the standard product description. The button calls the action_update_names method on sale.order, which recomputes the description of every line.

Both actions are manual: nothing is recalculated automatically. The user decides when to refresh prices or descriptions. The module only touches the sales order screen and the sale.order model; it does not change any other document or add any report, email or scheduled action.