Remove chat-based WECUI protocol. Everybody running a modern (1.2.5 or newer) WECUI should be fine.

This has a bonus of allowing us to stay far far away from that smelly PlayerChatEvent guy who's always late (or early, or both).

src/main/java/com/sk89q/worldedit/LocalPlayer.java

@@ -623,7 +623,9 @@ public abstract class LocalPlayer {
 
     /**
      * Send the CUI handshake.
+     * @deprecated Not used anymore; The CUI begins the handshake
      */
+    @Deprecated
     public void dispatchCUIHandshake() {
     }