Added the ability to set the quit message

src/main/java/net/minecraft/server/NetServerHandler.java

@@ -500,8 +500,10 @@ public class NetServerHandler extends NetHandler implements ICommandListener {
         // CraftBukkit start -- rarely it would send a disconnect line twice
         if (!this.c) {
             a.info(this.e.name + " lost connection: " + s);
-            this.d.f.a((Packet) (new Packet3Chat("\u00A7e" + this.e.name + " left the game.")));
-            this.d.f.c(this.e);
+            String quitMessage = this.d.f.c(this.e);
+            if (quitMessage != null) {
+                this.d.f.a((Packet) (new Packet3Chat(quitMessage)));
+            }
         }
         // CraftBukkit end
         this.c = true;

src/main/java/net/minecraft/server/ServerConfigurationManager.java

@@ -111,14 +111,16 @@ public class ServerConfigurationManager {
         ((WorldServer) entityplayer.world).manager.c(entityplayer); // CraftBukkit
     }
 
-    public void c(EntityPlayer entityplayer) {
+    public String c(EntityPlayer entityplayer) { // CraftBukkit - changed return type
         this.n.a(entityplayer);
         entityplayer.world.d(entityplayer); // CraftBukkit
         this.b.remove(entityplayer);
 
         // CraftBukkit start
         ((WorldServer) entityplayer.world).manager.b(entityplayer);
-        server.getPluginManager().callEvent(new PlayerQuitEvent(server.getPlayer(entityplayer))); // CraftBukkit
+        PlayerQuitEvent playerQuitEvent = new PlayerQuitEvent(server.getPlayer(entityplayer), "\u00A7e" + entityplayer.name + " left the game.");
+        server.getPluginManager().callEvent(playerQuitEvent);
+        return playerQuitEvent.getQuitMessage();
         // CraftBukkit end
     }