Simplified page level docblock

I think the current page level docblock is too long. I've look at some other projects to see how they implement this part. I propose I simplified docblock as follow:
```php
/**
 * PHPWord
 *
 * PHP version 5.3
 *
 * @copyright   2014 PHPWord
 * @license     http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt LGPL
 * @version     0.9.0
 */
```

If agreed, I'll make the changes.