Consistent usage of timestamps everywhere

When viewing some pages, like the Stacks, a timestamp is shown in a human-friendly way as “X days ago“, with an exact date/time as the tooltip. When viewing other pages, like the Stack Run History, a timestamp is shown as an exact date/time, with “X days ago” as the tooltip.

All pages that show a timestamp should be looked at for consistency.

If such a wholistic change is going to take place, the behavior should be changed, as well: Ideally, “recent” timestamps would show the human-friendly way, with a reversion to date/time once they are no longer “recent”. This “default” behavior should be configurable on the user settings page, such that users can pick “human recent”, “human always”, and “time stamp always”, as well as set the “recent” window.

As an additional implementation note: When showing human-friendly timestamps, it’s important that they update, as the page continues to be shown. It would be less than ideal to show that something was done 1 minute ago on a page that has now been loaded for an hour.