>KOOKY CABLE COMEDIES SHOWTIME GETS DEMENTED WITH three late-night summer comedy series. First up is Howie Mandel’s Sunny Skies (Fridays, 11:30 p.m. ET), a sketch-and-spoof jumble from the antic, often offensive comic. If you don’t like a skit, stick around. Mandel keeps the jokes coming. Midnight brings Full Frontal Comedy, a drearily risqué stand-up show hosted by Dom Irrera. Rim shots galore. The last entry is Twisted Puppet Theater (Sundays, 11 p.m. ET). The title says it all: marionettes with a sicko attitude (but few laughs). We’re not in Muppetville anymore, Toto.