Merge branch 'jc/revert-show-parent-info'

"git revert" learns "--reference" option to use more human-readable reference to the commit it reverts in the message template it prepares for the user. * jc/revert-show-parent-info: revert: --reference should apply only to 'revert', not 'cherry-pick' revert: optionally refer to commit in the "reference" format