Merge branch 'po/rebase-preserve-merges'

Various error messages that talk about the removal of "--preserve-merges" in "rebase" have been strengthened, and "rebase --abort" learned to get out of a state that was left by an earlier use of the option. * po/rebase-preserve-merges: rebase: translate a die(preserve-merges) message rebase: note `preserve` merges may be a pull config option rebase: help users when dying with `preserve-merges` rebase.c: state preserve-merges has been removed