Entertainment consumers are more and more turning from reality shows to those that offer perks such as, well, a plot. AMC Entertainment Holdings (AMCX) is fighting to be a player in this realm of original content. Home to “The Walking Dead,” “Breaking Bad” and “Mad Men,” the network on June 28 launched its newest series, “Humans.” The sci-fi drama debuted to an audience of 1.73 million, a solid showing by cable advertising standards. On Aug.