By Lauren R. Giannini Aiken, one of the great “escapes” for folks fleeing winter’s bite in the U.S. and Canada, is an equestrian wonderland for hunter-jumper shows, three-day eventing, foxhunting, steeplechasing and carriage driving, to name a few. If you’re headed to Aiken, you’re in for a treat. First-timers might want to compile a list