Discount % field to reflect Unit Price adjustment

In CRM v6, when you updated the unit price of a product on a quote line (e.g. reduce the price), the discount field was automatically updated to reflect the % that the item has been reduced by. This value can then be output to a quote table so the customer can see that the unit price has been discounted from the original price.

We are not able to do this in v7 and this has cause a little friction for migrating customers.

We could do this by having using a calculated field to do this and adding that field to the quote table or maybe even have a system option to "recalculate discount on price update"