bugfix : options can't be passed to SeparatorToSeparator via PluginManager

Hi,

When you try to create a SeparatorToSeparator via PluginManager, array options are not passed correctly to the Filter

This exemple
```
$filter = new Filter\FilterChain(array(
    'filters' => array(
        array(
            'name' => 'wordseparatortoseparator',
            'options' => array(
                'search_separator' => '/',
                'remplacement_separator' => '-'
            ),
        ),
     )
));

$filter('/path/to/file');
```
throws this error :
```
PHP Warning:  preg_quote() expects parameter 1 to be string, array given in ./vendor/zendframework/zendframework/library/Zend/Filter/Word/SeparatorToSeparator.php on line 94
```

My PR propose to change the Zend\Filter\Word\SeparatorToSeparator constructor argument to an array option, as all descending classes.

Cheers,
Patrick
place <code>{</code> at new line , see https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md#11-example