Goodness knows we could all use a laugh right now.  So this week we’re offering a Selected Shorts program full of funny stories selected by Andy Borowitz, who’s funny in so many ways. The late columnist Molly Ivins sticks it to pompous politicians in “Tough as Bob War and Other Stuff,” performed by Judith Ivey.  Essayist Sloane Crosley reveals a shameful habit in “The Pony Problem,” performed by Kirsten Vangsness.  Parker Posey delivers a classic Dorothy Parker rant (two Parkers, no waiting) about a lousy dance partner, and Selected Shorts’ late host and founder Isaiah Sheffer speaks truth to toddlers in Ian Frazier’s “Lamentations of the Father.”