This Sunday at 10p ET/PT, Showtime premieres the new comedy House of Lies, an apt nickname for the consulting firm of Galweather & Stearn, whose partners -- in the proud American tradition of high-stakes swindling -- connive their way into stacks-of-cash by any means necessary, be it number-bending, jargon-spouting, or a willingness to sleep with anything ambulatory.   Despite all their chicanery, the charmingly deceitful men and women of G&S do share at least one basic need with the businessmen they're so ruthlessly trying to rip off: a glorious after-work destination to set the stage for stimulating conversation and tie-loosening inebriation.