Edit sales and purchase invoices to include the receipt and payment

[Patch]

I suspect most of the functionality you are looking for is contained in this idea

Improvement to payment and receipt forms

It would be very helpful if the cash payment and receipt forms were improved to include several features: Linkage to customer/supplier subaccounts. Established customers don’t always buy on credit, making a sales invoice unnecessary. Likewise, businesses often pay cash to established suppliers, so purchase invoices are not needed. This linkage would eliminate separate invoice and spend/receive transactions. And it would allow the complete history of a customer/supplier in a statement, not jus…