FRIDAY: We like to think of Dame Edna as a sort of old-school Eddie Izzard, with only slightly worse eye shadow. The “glittering gigastar” is performing Dame Edna: Back With a Vengeance at the National Theater this weekend, and the title is probably somewhat telling — it sounds a bit like a last hurrah to us. Still, how many chances in life does one really have to be verbally abused and assaulted with gladiolus by…