This breaks capacities to overwrite fields per builders.
Imagine this generator:

```yaml
generator: admingenerator.generator.doctrine
params:
    ...
    fields:
        name:
            label: admin.model.label.name
            help:  admin.model.help.name
        pictureFile:
            label: admin.model.label.picture
            help:  admin.model.help.picture
            sortable: false
            dbType: string
            formType: single_upload
            addFormOptions:
                data_class:     Symfony\Component\HttpFoundation\File\File
        another:
            formType: collection
            ...

builders:
    actions:
        params:
            object_actions:
                delete: ~
    ...
    edit:
        params:
            fields:
                another:
                    addFormOptions:
                        options:
                            is_new: false
            title: "admin.model.title.edit|{ %name%: Model.name }|"
            tabs:
                admin.model.tab.general:
                    admin.model.fieldset.informations: [name, pictureFile]
                admin.model.tab.another:
                    NONE_another: [another]
            ...
```

Generation is not working because ``pictureFile`` main configuration is lost.


You can use this code to test this generator sample:

```php
function recursiveReplace($base, $replacement)
{
    $replace_values_recursive = function (array $array, array $order) use (&$replace_values_recursive) {
        $array = array_replace($order, array_replace($array, $order));

        foreach ($array as $key => &$value) {
            if (is_array($value))  {
                $value = (array_key_exists($key, $order) && is_array($order[$key])) ? $replace_values_recursive($value, $order[$key]) : $value;
            }
        }
        return $array;
    };

    return $replace_values_recursive($base, $replacement);
}

var_dump(recursiveReplace(
    array(
        'fields' => array(
            'another'=>array('dbType'=>'test','formType'=>'retest'),
            'pictureFile' => array('dbType' => 'mine')),
        'object_actions' => array('action1' => array('route' => 'my_route'), 'action2' => array('route' => 'my_again_route'))
    ),
    array(
        'fields' => array(
            'another' => array('dbType' => 'string')),
        'object_actions' => array('show' => null, 'edit' => null, 'action1' => null, 'action2' => null)
    )
));die;
```

var_dump is:
```

array(2) {
  ["fields"]=>
  array(1) {
    ["another"]=>
    array(1) {
      ["dbType"]=>
      string(6) "string"
    }
  }
  ["object_actions"]=>
  array(4) {
    ["show"]=>
    NULL
    ["edit"]=>
    NULL
    ["action1"]=>
    NULL
    ["action2"]=>
    NULL
  }
}
```
whereas we were waiting for:
```

array(2) {
  ["fields"]=>
  array(2) {
    ["another"]=>
    array(2) {
      ["dbType"]=>
      string(6) "test",
      ["formType"]=>
      string(6) "retest"
    },
    ["pictureFile"]=>
    array(1) {
      ["dbType"]=>
      string(6) "test"
    }
  }
  ["object_actions"]=>
  array(4) {
    ["show"]=>
    NULL
    ["edit"]=>
    NULL
    ["action1"]=>
    array(1) {
      ["route"]=>
      string(6) "my_route"
    }
    ["action2"]=>
    array(1) {
      ["route"]=>
      string(6) "my_again_route"
    }
  }
}

```


Not sure about ``action1`` and ``action2`` values... but the fact is that ``pictureFile`` is lost and template could not be generated.