Fix #129: Rework of #2225

This is fixed version of #2225.

```php
// Custom generator
CHtml::setModelNameConverter(function($model) {
    $module    = Yii::app()->getController()->getModule();
    $classname = is_object($model)
        ? get_class($model)
        : (string) $model;

    return $module && $module->getId() !== 'gii'
        ? 'model_'.md5($classname)
        : $classname;
});

// Getting form params
if (isset($_POST[CHtml::getNameByModel($model)])) {
    // ...
}
```