Add a flag to keep meta data

It would be great to have a flag/something in the setup so that when an output dataset is created, it definitely inherits all meta data from the input dataset, regardless of whether the output is a different name.

Use case:
I have an input dataset "spectrum", and subtract a background. I return a "spectrum_no_background" and "background" dataset. Unless I explicitly copy the dictionary to the output dataset, no metadata is carried over. This is particularly import since the axis arrays are not copied.