The long-awaited film, starring Idris Elba, made a disappointing $19.5M
                                
                                
                                    (Newser) -
                                    After a decade of development and several postponements, the long-awaited Stephen King adaptation The Dark Tower debuted with an estimated $19.5 million in North American ticket sales, narrowly edging out the two-week leader Dunkirk,  AP  reports. The so-so result for The Dark Tower, starring Idris Elba and Matthew McConaughey,...