BUG: copy.(deep)copy should preserve F-contiguity

Currently, copy.deepcopy() on certain objects in scikit-learn results in the copied object being broken, as underlying methods depend on members being F-contiguous. I can think of no reason that F-contiguous arrays should not remain F-contiguous through a copy.copy/copy.deepcopy, therefore this alters the methods to use NPY_KEEPORDER when allocating the copy.