Tom Stoppard's new play was enjoying a sold-out run when venues closed. Its producer, Sonia Friedman, recalls how the crisis unfolded Leopoldstadt in limbo: Tom Stoppard, Patrick Marber and other crew members interviewed Tom Stoppard's Leopoldstadt was just beginning its eighth sold-out week at Wyndham's theatre in London's West End when the order came through that it was shutting down. Greeted as a late-period maste…