Update ffmpeg to version 20170821-d826951
Update ffmpeg to version 20170821-d826951

coonce/scoop,yunspace/scoop,berwyn/scoop,kodybrown/scoop,vidarkongsli/scoop,Cyianor/scoop,Congee/scoop,lukesampson/scoop,rasa/scoop,reelsense/scoop,toxeus/scoop,nikolasd/scoop