Merge branch 'js/name-rev-use-oldest-ref' into maint

"git describe --contains" often made a hard-to-justify choice of tag to give name to a given commit, because it tried to come up with a name with smallest number of hops from a tag, causing an old commit whose close descendant that is recently tagged were not described with respect to an old tag but with a newer tag. It did not help that its computation of "hop" count was further tweaked to penalize being on a side branch of a merge. The logic has been updated to favor using the tag with the oldest tagger date, which is a lot easier to explain to the end users: "We describe a commit in terms of the (chronologically) oldest tag that contains the commit." * js/name-rev-use-oldest-ref: name-rev: include taggerdate in considering the best name