Another issue being debated yesterday was whether Aron would be allowed to sit shiva – the seven-day mourning period in Jewish tradition – at the house in Williamsburg where the rebbe had lived.Zalmen supporters were arguing that Aron had violated an unsigned agreement between the two sides by asking his son, Mendel, to deliver a eulogy at the end of the second funeral for Moses Teitelbaum in Kiryas Joel yesterday morning. They claim no grandchildren of the grand rebbe was supposed to speak at the two funerals.That dispute triggered a brief confrontation in the Kiryas Joel synagogue about 4:50 a.m., as Aron shouted and partisans packed tightly in the front of the synagogue threw punches. Shortly afterward, Zalmen supporters whisked the casket through the crowd and out the front door, with no speech from Mendel Teitelbaum…………