Save result in hisotory for selected test run

[ghost]

Now tool shows current and only previous run.

It would be nice to select and save results with comments after certain site changes, so after more runs you could see what improvement increased site score most, because after 10 runs I can't remember what results were on initial run and can't say how much I improved my site.

So there could be an option so set a flag to "save this run" and add comment to it, and store those runs in file, and then display in UI all saved instances.