Remove flux and luminosity attributes for now, and finish renaming analysis properties

Until we figure out how to properly compute the flux and luminosity of structures (as discussed in #47) I think we should remove these properties, which is done in this PR. Once we agree on how to deal with fluxes, we can re-implement them (but better start off without an implementation than with an implementation that could be wrong in some cases)

In addition, I have renamed the properties I had not renamed before, and I think the full set of properties has more consistent and clear names. This addresses #48.

@ChrisBeaumont - could you review this?