2.6 toList() localization

Currently it is not possible for a non English context to use the defaults of toList().
You would always have to provide the second argument:

    echo $this->Text->toList($list, __('and'));

With this change it is possible to do

    echo $this->Text->toList($list);

and have the "and" translated.

Also, for using the third argument, you dont have to retype the word again, this suffices:

    echo $this->Text->toList($list, null, ' - ');

This change is 100% BC.