AssetManager: clearing browser's cache on site update

Comparing #2 with #3

Content

[...]

if ($this->_assetsBase === null) {
$this->_assetsBase = Yii::app()->assetManager->publish(
Yii::getPathOfAlias('application.assets'),
false,
-1,
defined('YII_DEBUG') && YII_DEBUG
);
}
return $this->_assetsBase;
}

[...]