[minorgod]

After some testing, I've determined that it's not a good idea to add the free shipping cost to the discounts because it screws up the order receipts and makes it look like the customer is being overcharged because it shows up as a discount in the receipt, but the order total doesn't reflect the discount because we're simply not charging shipping, so nothing needs to be subtracted when it isn't added in the first place. That sounds confusing, so I've modified my post above and commented out the addition of the shipping charges to the discounts, so free shipping will no longer show as a discount. Aside from that it seems to work great for me.