do not store the field as shared product can have different supplier
depending on the company logged
Use compute as related will always pick the first one whatever the
company logged
product_usability: add seller_id field
base_usability: write/create rights on res.partner.title to base.group_system (instead of partner manager)
sale_stock_usability: move warehouse_id to top
stock_usabiluty: type on product set to 'product' by default
