LOS ANGELES, Sept 20 (Reuters) - Premium cable network HBO dominated television's Emmy awards on Sunday with trophies for best comedy "Veep" and best drama "Game of Thrones," holding off challenges from the digital upstarts that have shaken up traditional Hollywood. HBO, owned by Time Warner Inc, topped all networks and their streaming competitors with a total of 43 awards. It was the first time in 13 years a network won both the drama and comedy series honors. Online retailer Amazon.com shared the Emmy stage, taking five awards for groundbreaking transgender series "Transparent," including best actor for Jeffrey Tambor. Streaming pioneer Netflix earned four Emmys, with Uzo Aduba named best supporting drama actress for playing "Crazy Eyes" on the dark prison series "Orange is the New Black." Emmy awards bring... More