The "author-script" file "git rebase -i" creates got broken when
we started to move the command away from shell script, which is
getting fixed now.
* es/rebase-i-author-script-fix:
sequencer: don't die() on bogus user-edited timestamp
sequencer: fix "rebase -i --root" corrupting author header timestamp
sequencer: fix "rebase -i --root" corrupting author header timezone
sequencer: fix "rebase -i --root" corrupting author header