lls_fit_gaussian is now deprecated, use lmfit_gaussian instead for more accurate sx/sy; neaten up function args a bit

forgot to pull before pushing

make _perform_actions available for other commands and add better handling of command-line args for modularity

forgot to pull before pushing

update docstrings, add 'alldefaults' to interactive mode, add 'digital' and 'analog' back to CLI mode

update timings (update not complete) and add option for subtracting background from numbers reported in results.toml