Merge branch 'cc/replace-graft' into next
"git replace" learned a "--graft" option to rewrite parents of a
commit.
* cc/replace-graft:
replace: add test for --graft with a mergetag
replace: check mergetags when using --graft
replace: add test for --graft with signed commit
replace: remove signature when using --graft
contrib: add convert-grafts-to-replace-refs.sh
Documentation: replace: add --graft option
replace: add test for --graft
replace: add --graft option
replace: cleanup redirection style in tests