| ⇢ | A | MaintenanceController added |
| ⇢ | A | SystemService::switchMaintenance() added | |
| ⇢ | A | MaintenanceController::index() added | |
| ⇢ | A | MaintenanceController::__construct() added | |
| ⇢ | A | SystemService::isMaintenanceMode() added | |
| B | ↘ | C | PluginController::enable() got worse |