Fixed bug which occurred in test_convelemwise_tanh

When the pool shape is equal to the pool stride, theano's max pooling algorithm is called instead of pylearn2's one.
Are you sure the last parameter is True? If the input of max_pool() is of shape 5x5 and the pool_shape==pool_stride==2x2. What max_pool() output size is? 2x2 or 3x3? I was under the impression that it is 3x3, as it pad with inf.