To Americans, French stuff can be a little intimidating. Who hasn't circled around a dome of fois gras waiting for someone more Frenchy to take the first greasy swipe? OK, maybe that's just me. But you probably think French people like to laugh at our manners and mores, right? They sometimes do. When Todd VanAmburgh and the sparkling cast of Seabury's "The Learned Ladies" invite us into Madame Philamente's wacky 17th-century parlor, we realize they also like to laugh at themselves and their own silly, foppish Frenchness.