Refixed last commit + OnLeave

- Order is now 4. Hook-order works by priority, so this will now allow
Nicks to properly work with TShockIRC.
- OnLeave shall no longer throw unhandled exceptions when Terraria
Server Listings attempt to connect.
- TShock.Utils.Broadcast -> TSPlayer.All.SendMessage at the OnChat hook
(didn't bother checking the whole plugin).

So yeah. This one has been tested and seems to work. Order seems to work the opposite way in Hooks as it does in Plugin Loading :/.