append the original path extension to the hash filename. closes #967
append the original path extension to the hash filename. closes #967

odyth/SDWebImage,ruaho/SDWebImage,iheartradio/SDWebImage,zhang-yawei/SDWebImage,iosnatarajan/SDWebImage,smule/SDWebImage,zllbird/SDWebImage,cochat/SDWebImage,dreampiggy/SDWebImage,Deyine/SDWebImage,altrooz/SDWebImage,tokorom/SDWebImage,heroims/SDWebImage,rs/SDWebImage,ikesyo/SDWebImage,awkward/SDWebImage,tualatrix/SDWebImage,klundberg/SDWebImage,dreampiggy/SDWebImage,Insfgg99x/SDWebImage,mattjgalloway/SDWebImage,twobitlabs/SDWebImage,dreampiggy/SDWebImage,irealme/SDWebImage,bpoplauschi/SDWebImage,buleSky111/SDWebImage,awkward/SDWebImage,dpettigrew/SDWebImage,geoffmacd/SDWebImage,HannaLu/SDWebImage,iMinichrispy/SDWebImage,nickhingston/SDWebImage,amyhametov/SDWebImage,awkward/SDWebImage,Frntbac/SDWebImage,yunzhongyoulong/SDWebImage,smyrgl/SDWebImage,ttgb/SDWebImage,masterfego/SDWebImage,Kekanto/SDWebImage