Created a new Class to be able to generate queries like "where NOT (X)"

this class can create sql query conditions like "where NOT (a=b OR x <> y)"
please use ZF license header : 
```
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 */
```