Asset Bundle remap feature

How this can be used:

```php
'assetManager' => [
    'bundles' => [
        'yii\web\JqueryAsset' => [
            'class' => 'app\assets\JqueryAsset',
        ],
    ],
],
```

By doing this you can fast remap existing asset bundle to another custom class. Without that feature you need override **all classes** which depends on 'yii\web\JqueryAsset'.