In a medium bowl, mash cranberry sauce with a fork or a potato masher. Stir in sugar, cranberry juice, mustard, and cloves. Place pork roast in slow cooker and pour cranberry sauce mixture over it. Cook on low setting for 6 to 8 hours or until meat is tender. Remove roast and keep warm. With a metal spoon, skim the fat from the liquid in the slow cooker. Pour 2 cups of the liquid (add water to fill out the measure, if necessary) into a small saucepan. Bring to a boil over medium-high heat. Blend cornstarch and cold water to make a paste; stir gradually into boiling liquid. Continue cooking, stirring constantly, until mixture thickens. Add salt to taste. Serve with pork Makes dozen servings.