Memory usage of printing DArrays

[malmaud]

Moving from https://github.com/JuliaLang/julia/issues/2771#issuecomment-148172159

[andreasnoack]

Fundamentally, I think this is a base issue, but it might be simpler to fix here. In general, I don't think that base should think it's okay to scalar index abstract arrays. We could modify the base printing method to copy the chunks into an Array before all the scalar indexing business. We could also redo the printing here but that would be a lot of code duplication.