Changes

Add new plots and calculations to dashboard.
These include a weighted bias ratio that tells us
how much the tuner's recommendation is expected to improve the fit.
It also includes an estimate of the overall sensitivity of each metric,
i.e., how "unbudgeable" the metric is.
It also automatically deletes the smallest singular values.
Finally, it includes an option to leave uninteresting metrics
at their default values, but this option is commented out for now.

For #910.

I changed the name to calc_responder_driver because I thought that
calc_responder_var_lev (which it had recently been changed to) wasn't
very fitting.