Remove unncecessary overloads of __getstate__ and __deepcopy__
Remove unncecessary overloads of __getstate__ and __deepcopy__

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