This commit adds support for `--ignore-date` which is passed to `git am`
to easily change the dates of the rebased commits.
Signed-off-by: Pratik Karki <predatoramigo@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>