Git commit command has `cleanup` argument (
https://git-scm.com/docs/git-commit#git-commit---cleanupltmodegt)
which can clean up commit messages after some cutline.

This cutline appears when you make commit with
git commit -v
(-v, --verbose add diff to commit message)

This commit add cutting of commit message after this cutline

Git has oppurtunity to set custom comment char.
Add retriving this char from config and handle on message parsing

Suggested by @jorisroovers to properly test use-case for git scissors
line since commented lines are being ignored regardless.