PLEASE make updates to invoices


1. A function really needs to be added to the invoice that allows us to select items from our inventory. When we email the invoice to the customer, it should also automatically change the "current quantity" to "quantity committed". That way it will remove the item from being purchased by anyone else. This will alleviate problems with having to do it manually or end up selling the items needed for the customer and having to reorder. This also needs to detect any discounts and show the original and new costs.

2. Add a check box for tax. We shouldn't have to add up the tax manually and then make another line item.