rename a comitter (works with AUTHOR in place of COMITTER, of course)

comitter rename

git filter-branch -f --commit-filter '
        if [ "$GIT_COMMITTER_NAME" = "name" ];
        then
                GIT_COMMITTER_NAME="New Name";
                GIT_COMMITTER_EMAIL="new@email.com.com";
                git commit-tree "$@";
        else
                git commit-tree "$@";
        fi' -- --all