Small phpdoc fix in Klein\Request
Small phpdoc fix in Klein\Request

Klein\Request::param may return null, if there is no key and default is null.

Also it may return array, if html form contains inputs like is like:

```html
<input type="hidden" name="id[]" value="1">
<input type="hidden" name="id[]" value="2">
<input type="hidden" name="id[]" value="3">
```

```php
<?php
// $ids will contain array of ids
$ids = $request->param('id');
```
chriso/klein.php,klein/klein.php