Called when a message is printed to the chat box. Note, that this isn't working with player messages even though there are arguments for it.
1 number index
The index of the player.
2 string name
The name of the player.
3 string text
The text that is being sent.
4 string type
Chat filter type. Possible values are:
- joinleave - Player join and leave messages
- namechange - Player name change messages
- servermsg - Server messages such as convar changes
- teamchange - Team changes?
- chat - (Obsolete?) Player chat?
- none - A fallback value
Return true to suppress the chat message