Show min/max result info

[tobami]

The overview table, and the timeline plots should show min/max information when available

[tobami]

The overview table already shows min/max columns when values are present. The timeline tooltips do not show that information yet, however.

[str4d]

The timeline plots show min/max info in the tooltips, and extrema bands, for median benchmarks as of #203. Per #203 (comment) the next step would be to extend this to mean benchmarks.

[tobami]

min max is shown so we can close this issue. Thanks for noticing!