replaced isnan and isinf
replaced isnan and isinf

tkerola/chainer,hvy/chainer,niboshi/chainer,chainer/chainer,keisuke-umezawa/chainer,niboshi/chainer,chainer/chainer,okuta/chainer,okuta/chainer,hvy/chainer,keisuke-umezawa/chainer,wkentaro/chainer,chainer/chainer,wkentaro/chainer,wkentaro/chainer,pfnet/chainer,keisuke-umezawa/chainer,keisuke-umezawa/chainer,niboshi/chainer,chainer/chainer,okuta/chainer,hvy/chainer,hvy/chainer,wkentaro/chainer,okuta/chainer,niboshi/chainer