Fixes #795: do not generate form-control css class for file input as it would display an unneeded border.

```php
normalizeItems($items, &$active)
```
Qiang use 
```php
$items[$i]['items'] = $this->normalizeItems($item['items'], $route, $hasActiveChild);
```
So $hasActiveChild not assign value and parent item not set activated

Plz, review and approval

Thanks

Added GridView::dataColumnClass.