Function db_engine
Return the database engine of the given namespace
		Package: PHPLucidFrame\Core
Copyright: Copyright (c), PHPLucidFrame.
License: MIT License This source file is subject to the MIT license that is bundled with this source code in the file LICENSE
Author: Sithu sithu@phplucidframe.com
Located at helpers/db_helper.mysqli.php
	
	Copyright: Copyright (c), PHPLucidFrame.
License: MIT License This source file is subject to the MIT license that is bundled with this source code in the file LICENSE
Author: Sithu sithu@phplucidframe.com
Located at helpers/db_helper.mysqli.php
string | 
		$namespace = null | 
		Namespace of the configuration to read from | 
			string
		 | 
		Database engine name |