Print commit time/date from perspective of committer.
Previously, it was printed in the time zone of the reader, but with
the committer's time zone offset. It is now consistent.
1:3aa14bbc23d90:8633637036c13aa14bbc23d9 tip8633637036c18633637036c1+8633637036c13aa14bbc23d9 tipmerging file13aa14bbc23d9 tip3aa14bbc23d9 tip3aa14bbc23d9 tip3aa14bbc23d9 tip