Come up with a better dataset naming scheme

[hershal]

I'm using Points and Labels to describe a data set, but those are still ambiguous. Ideally we should have something like:

Dataset (e.g. CIFAR-10) -> Batch (e.g. a fold) -> Datamap (e.g. array of pixels and an associated classification of those pixels)

[EricCrosson]

How does an array of pixels and associated classifications give us any different information from 'points and labels'?

[hershal]

The problem is when I refer to "points" in most places I really mean a batch of points, i.e. 5000x3072. I suppose I could rectify this ambiguity by renaming the variable to batch_points (or equivalent).

[hershal]

See PR #13