Last year, social game-maker Zynga acquired OMGPOP for roughly $200 million. OMGPOP is the development house behind the once-incredibly popular Draw Something. Today, Zynga is shutting OMGPOP down as part of another round of layoffs at the company. Zynga has laid off 18 percent of its staff -- 520 employees -- reports AllThingsD. The move today will affect every part of the San Francisco social gaming company and cut