Chatroom list integration.php hook

[Trevorhawes]

Suggestion: Provide in integration.php a hook to get the chatroom list available (with default SQL as already set in includes/json/receive/receive_chatroom_list.php )
(I need to show only certain chat rooms to certain people at certain times)

Again, simple to do. For the moment, I have modified AC to do what I need, but in an upgrade this will get overwritten - hence a little hook would be a simple and welcome addition.