In a small bowl, sprinkle gelatin over water; let stand 1 minute. In a saucepan, combine sugar, cornstarch and salt. stir in eggnog until smooth. Bring to a boil; cook and stir for 2 minutes or until thickened. Stir in gelatin until dissolved. Remove from the heat; cool to room temperature. Stir in extracts; fold in whipped cream. Pour into pastry shell. Refrigerate until firm.