bug fix about batch_shape and event_shape for distributions.Independent
bug fix about batch_shape and event_shape for distributions.Independent

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