Where possible maintain naming of C++ library

[cheesema]

e.g. min_level vs level_min

We should go for level_min, otherwise this will just create frustration, and there is little clarity gain from the first, except I agree it sounds better. (But the second aligns with the paper)

[cheesema]

Same with smoothing and error_bound, atleast for now. But its just gonna cause headaches unless they are aligned where it makes sense.