 Add RReLU in the reference manual
 Add RReLU in the reference manual

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