Zend\Stdlib\ArrayObject::offsetExists() returning by reference

Since the release of Zend Framework 2.1.1 I have got the following error message when developing:

```php
Fatal error: Declaration of Zend\Stdlib\ArrayObject::offsetExists() must be compatible with that of ArrayAccess::offsetExists() .../vendor/zendframework/zendframework/library/Zend/Stdlib/ArrayObject.php on line 25
```

The problem is, that the latest version of debian squeeze only provides php5 (5.3.3-7 source: http://packages.debian.org/squeeze/php5).
The returning by reference feature from the ArrayAccess::offsetGet() method is only implemented since version 5.3.4 (Starting with PHP 5.3.4, the prototype checks were relaxed and it's possible for implementations of this method to return by reference. source: http://www.php.net/manual/en/arrayaccess.offsetget.php).

There is no stable release from debian which provides a greater php version. So everyone which uses debian squeeze has to compile a newer php version by themself.  

The current system requirements from Zend Framework 2 are 5.3.3 (source: https://github.com/zendframework/zf2). Did you bump up the requirements to php 5.3.4 for ZF 2.1.1 on purpose?