Madness has always fascinated Werner Herzog, but the insanity of the German director’s newest film almost resembles the work of its producer, David Lynch. The elliptical My Son, My Son What Have Ye Done (out now on DVD) even features a dwarf in a tuxedo! Michael Shannon (currently starring in HBO’s “Boardwalk Empire”) plays a psychotic young actor who kills his intrusive mother with a sword and holes up in their home as the police negotiator (Willem Dafoe) plays for time. Much of the film consists of flashbacks, zigzagging through episodes of erratic behavior but ultimately explaining nothing. That, too, looks a lot like Lynch.