Added a template operator: $obj | to_array( $level=2, $attributes=array() )
It allows encoding to php array any ezpersistentobject (ie. all the 'objects' in
the online manual http://ez.no/doc/ez_publish/technical_manual/4_x/reference/objects)
It is useful for data export as well as using json_encode / xml_encode from ezjscore.
example usage: {json_encode($current_user|to_array(1))}
The 1st param is the nesting level used for sub-objects (same as |attribute() does).
The 2nd param, if non empty, is a filter on the attributes of $obj that will be
returned (note: it is not applied recursively).