change-all-mine-commit-emails.sh

git filter-branch -f --commit-filter '
        if [ "$GIT_AUTHOR_EMAIL" = "<old-email>" ];
        then
                GIT_COMMITTER_EMAIL="<new-email>";
                GIT_AUTHOR_EMAIL="<new-email>";
                git commit-tree "$@";
        else
                git commit-tree "$@";
        fi' HEAD