By Alexei Oreskovic SAN FRANCISCO (Reuters) – Yahoo Inc bolstered its line-up of online video programming on Monday with two original comedy series and a new Web channel that will stream live concerts. The two comedy series, which Yahoo will show on its website next year, are the first long-form original comedies in Yahoos growing selection of online video. Each series will consist of eight 30-minute episodes which Yahoo will post on its website all at once. The new programs underscore the struggling Web portals efforts to bolster its traffic and its advertising revenue by streaming more video programs on its website.