Added Viterbi decoder for sequence labelling
Added Viterbi decoder for sequence labelling

yanqingmen/Wapiti,Jekub/Wapiti,yanqingmen/Wapiti,yanqingmen/Wapiti,yanqingmen/Wapiti,yanqingmen/Wapiti,Jekub/Wapiti,Neseb/wapiti,Neseb/wapiti