[download_cart] and [download_checkout] don't work well together

[henrywright]

If the [download_cart] shortcode is used on the same page as the [download_checkout] shortcode and an item is removed from the cart using the "remove" facility in [download_cart], the information output by [download_checkout] isn't updated.

To reproduce

1. Create a checkout page and use the [download_checkout] shortcode in the content area
2. Create a sidebar area in the newly created checkout page and use the [download_cart] shortcode
3. Add a few items to the cart
4. Visit the checkout page and try to remove one of the items using the "remove" facility in the sidebar provided by [download_cart]

You will notice the item is removed from the sidebar area which is controlled by [download_cart] but the item isn't removed from the main content area which is controlled by [download_checkout]

Interestingly, if you use the "Remove" facility provided by [download_checkout], the item is removed from both the sidebar area and the main content area. In this case the "Remove" button works well.

[henrywright]

Amir kindly suggested I use the blocks instead.