BELGRADE, Serbia — Amy Winehouse was booed and jeered during a concert in Serbia's capital as she stumbled onto the stage, mumbled through her songs and wandered off.Serbian media described the concert late Saturday kicking off her European tour before some 20,000 fans as a "scandal" and a "disaster." The Blic daily said the concert was "the worst in the history of Belgrade."Read More... More on Amy Winehouse