ZF-11805: Zend_Navigation_Page error messages don't contain enough information
Using a navigation.ini file, it is really easy to typo or make a mistake.
In Zend_Navigation_Page the exception 'Invalid argument: Unable to determine class to instantiate' on line 235 is really hard to fix. It should show the line that caused the error and why (e.g. no parent page, no container named 'blah' or something)