Better commit date format when older than N days (BB-8076)

In the commit history the 'Date' column shows 'x days ago' up to a month ago. This quickly (beyond a day or two ago) gets very unhelpful, 21 days ago makes much less sense that Feb-22. While I can hover over each date individually to get the date, this is fiddly and means they have to be checked one at a time.

Switching to a date for anything before yesterday, or even up to five days ago would be much easier to interpret.