[VirtualBox/el7] (6 commits) ...script helper update

Summary of changes: 99fcea2... - Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass (*) c969f91... - Rebuilt for https://fedoraproject.org/wiki/Fedora_29_Mass (*) 7631874... Update VBox to 5.2.18 (*) 25ad134... update script with new branch (*) f5b0ad6... Update VBox to 5.2.20 (*) 5f0ffe3... script helper update (*) (*) This commit already existed in another branch; no separate mail sent