My all-time favorite episode of The Simpsons – and by “all time,” I’m going back 30 years now, to its 1989 Christmas special – is its “Itchy & Scratchy & Marge” installment from 1990, when Marge organizes a protest against the violence in the cartoons watched by her impressionable children. (Itchy and Scratchy, the perennial and bloody rivals, are rewritten to placate the protesters, resulting in boring cartoons that drive the kids outside to play.) Tonight’s new episode might be considered an homage, even a sequel: It’s called “Bart vs. Itchy & Scratchy,” and has Bart reacting to an all-female reboot of “The Itchy & Scratchy Show”…