Smart Coupons

Shoppers from Shipping Zones which do NOT allow Free Shipping are still able to apply a coupon code giving them free shipping. this is because the only way to create a coupon which gives Free Shipping is to have it be tied to a Cart or Product discount. We need the plug-in to add a category of coupon which grants Free Shipping only (no Cart or Product discount), so that after a person adds their address the coupon–though it was applied already–would create an error such as, “Your shipping destination makes you ineligible for this coupon.”