Two additional user groups - Banned & Custom

The banned user group (AJAX_CHAT_BANNED) is not permitted to enter the chat regardless of the chat's open/closed status. This could be set to a forum's default banned group to deny them access to the chat. The banned group addition is on top of the chat's own per-user kick/ban functionality which is time-limited.

The additional custom user group (AJAX_CHAT_CUSTOM) mirrors the standard user class permissions, but permits distinctive username colours via CSS edits. Example would be VIP group, contributors, etc standing out from standard users. Not everyone using AJAX Chat may want utilise an extra group, but I think having the hard yards already complete would be welcomed by those who would like the extra group.

The colour for the custom group varies depending on the style. In the case of prosilver, the color is a sky blue shade:
![ajaxchat---additional-usergroup---prosilver](https://f.cloud.github.com/assets/3396137/2019480/db9b9670-8823-11e3-9d6e-e8403e20c507.jpg)

To utilise these two additional user classes some editing to a forum's respective CustomAJAXChat.php file would be required. I personally use the SMF version of AJAX Chat, and while SMF's process of banning doesn't utilise a 'banned' user group, I am able to put any members who abuse the chat into a custom group manually. This then locks them out of the chat indefinitely using this modification, until they are removed from the respective group via SMF.

Here's an example of what could be added to CustomAJAXChat.php to flag an SMF member group of ID 12 to be Banned indefinitely. The ID number will vary depending on your SMF forum configuration.
```php
			elseif(in_array(12, $user_info['groups']))
				$userData['userRole'] = AJAX_CHAT_BANNED;
```

I'm not all that familiar with the latest versions of other supported forum software so can't give an example for those.