15% faster conv fwd pass for 48N filters.
15% faster conv fwd pass for 48N filters.

soumith/cuda-convnet2.torch,soumith/cuda-convnet2.torch,ajtao/my_ccn2_t,monikajhuria/cuda-convnet2.torch-master_update,szagoruyko/cuda-convnet2.torch,szagoruyko/cuda-convnet2.torch,szagoruyko/cuda-convnet2.torch,szagoruyko/cuda-convnet2.torch,ajtao/my_ccn2_t,monikajhuria/cuda-convnet2.torch-master_update,monikajhuria/cuda-convnet2.torch-master_update,ajtao/my_ccn2_t,soumith/cuda-convnet2.torch