Purchase Request should be decoupled from the stock_supply module
Following the purchase requisition discussion https://discuss.tryton.org/t/purchase-requisition/47 which resulted in the idea of decoupling the purchase request from the stock_supply module https://discuss.tryton.org/t/extract-purchase-request-from-stock-supply-module/55 in order to increase their modularity.
This issue is here to track the developments.