Ken Jacobson, one of the pioneers of talent management, died on Thursday after more than three decades as a manager. I hear he was found unresponsive in his home after suffering an injury within the past week. For 20 years, Jacobson was a founding partner of management firm James/Levy/Jacobson. Working alongside his partners, Jacobson was involved in launching the careers of such actors as James and Dave Franco, Jennie Garth, Jaimie Alexander, Michelle Williams, Mark-Paul…