LAS Vegas, Nevada, May 18 (Reuters) — Taylor Swift dominated the 2015 Billboard Music Awards on Sunday (May 17), winning eight awards including top artist, while British soul singer Sam Smith took the honors for both top male artist and new artist. Swift, 25, one of the top-selling musical acts in the United States last year, also picked up awards for top female artist, top Billboard 200 artist and album and top hot 100 artist, […]