For each given data set, calculate a curve that traces the lowest N points over specified bins.
lowestcurve points <# lowest> [step <stepsize>] <dset0> [<dset1> ...][out <file>] [name <setname>]
<# lowest> Number of lowest points in each bin to average over.
[step <stepsize>] Bin step size
<dset0> [<dset1> ...] Data set(s) to use.
[out <file>] File to write lowest curve to.
[name <setname>] Output lowest curve set name.
Calculate a curve of the average of the # lowest points in bins of stepsize. Essentially each input data set is binned over bins of stepsize, then the lowest <#> points are averaged over for each bin.