Description:
------------
When I try to overload the function in parent class by just assigning the function argument a default value, the interpreter complains (when running in strict mode)

Reproduce code:
---------------
class Node {
    public function process($param) {
    }
}
       
class Node_FrontController extends Node {
    public function process($param=null) {
    }
}


Expected result:
----------------
No warning message

Actual result:
--------------
Strict Standards: Declaration of Node_FrontController::process() should be compatible with that of Node::process() in FrontController.inc.php on line 25