Added pybind binding for tan, arcsin, arccos, arctan
Added pybind binding for tan, arcsin, arccos, arctan

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