Added concat()
Added concat()

Fixes toots/buffer-browserify#6

loon3/buffer,kawanet/buffer,LinusU/buffer,beni55/buffer,mafintosh/buffer,beni55/buffer,LinusU/buffer,jessetane/buffer,feross/buffer,btd/buffer,kawanet/buffer,nolanlawson/buffer,SAGV/buffer,feross/buffer,btd/buffer,SAGV/buffer,substack/native-buffer-browserify,nolanlawson/buffer,LiuDeng/buffer,loon3/buffer,feross/buffer,mafintosh/buffer,LiuDeng/buffer,toots/buffer-browserify