X-Mas in September hits St. Louis with three festivals tailored to most of the city's show-going population. LouFest descends on Forest Park with the likes of Snoop Dog, Run the Jewels and more while the Wayback edition of Pointfest offers a nostalgic power-trip at the Hollywood Casino Amphithreatre on Sunday.Those who prefer to dig a little deeper into underground music should look into Pü Fest over at 2720 Cherokee Street.…