Merge branch 'jn/cherry-revert-message-clean-up'
* jn/cherry-revert-message-clean-up:
tests: fix syntax error in "Use advise() for hints" test
cherry-pick/revert: Use advise() for hints
cherry-pick/revert: Use error() for failure message
Introduce advise() to print hints
Eliminate “Finished cherry-pick/revert” message
t3508: add check_head_differs_from() helper function and use it
revert: improve success message by adding abbreviated commit sha1
revert: don't print "Finished one cherry-pick." if commit failed
revert: refactor commit code into a new run_git_commit() function
revert: report success when using option --strategy