Support method beforeQuery of Model

```php
<?php

class Robots extends \Phalcon\Mvc\Model {
}

class GooleRobot extends Robots {
	
    public function getSource()
    {
		return 'robots';
    }

    public function beforeQuery($builder)
    {
		$builder->andWhere('type = :type:', array('type' => 'google'))
    }
}
```