git_recent_tag fails to return "The most recent tag."

git_recent_tag is documented to return "The most recent tag."

In my hands, it does not reliably do this.

The implementation seems to assume that `git tag` results are necessarily in order of their creation, but this is not true.

I expect the following is a better implementation:

git_recent_tag<-function () utils::head(git('tag  --sort=-taggerdate')$stdout,1L)

