note 11839 added to language.types.php

I forgot to mention that Resource, Null types are only in PHP4 (Bool, too?) That's why they are not described in this manual, I suppose. I think it time to freeze manual for PHP3 users, place it some where on the site. PHP4 has more things that need to be documented in this manual. I still can view the code to see if new functions are added and use them, but I feel uncomfortable to use new functions/statements if they are not documented. (Changes in API may break my PHP4 codes in the future) http://www.php.net/manual/en/language.types.php