Simplify stop condition and iteration to override epoch
Simplify stop condition and iteration to override epoch

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