Merge branch 'jc/conflict-hint' into cc/interpret-trailers-more

* jc/conflict-hint: merge & sequencer: turn "Conflicts:" hint into a comment builtin/commit.c: extract ignore_non_trailer() helper function merge & sequencer: unify codepaths that write "Conflicts:" hint builtin/merge.c: drop a parameter that is never used git-tag.txt: Add a missing hyphen to `-s`