[Bleeding] Changed event system into a new, much faster design. Huge thanks to @zml2008 & @lahwran.

src/main/java/org/bukkit/event/inventory/FurnaceBurnEvent.java

@@ -3,6 +3,7 @@ package org.bukkit.event.inventory;
 import org.bukkit.block.Block;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
 import org.bukkit.inventory.ItemStack;
 
 /**
@@ -10,6 +11,7 @@ import org.bukkit.inventory.ItemStack;
  */
 @SuppressWarnings("serial")
 public class FurnaceBurnEvent extends Event implements Cancellable {
+    private static final HandlerList handlers = new HandlerList();
     private Block furnace;
     private ItemStack fuel;
     private int burnTime;
@@ -87,4 +89,13 @@ public class FurnaceBurnEvent extends Event implements Cancellable {
     public void setCancelled(boolean cancel) {
         this.cancelled = cancel;
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

src/main/java/org/bukkit/event/inventory/FurnaceSmeltEvent.java

@@ -3,6 +3,7 @@ package org.bukkit.event.inventory;
 import org.bukkit.block.Block;
 import org.bukkit.event.Cancellable;
 import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
 import org.bukkit.inventory.ItemStack;
 
 /**
@@ -10,6 +11,7 @@ import org.bukkit.inventory.ItemStack;
  */
 @SuppressWarnings("serial")
 public class FurnaceSmeltEvent extends Event implements Cancellable {
+    private static final HandlerList handlers = new HandlerList();
     private Block furnace;
     private ItemStack source;
     private ItemStack result;
@@ -67,4 +69,13 @@ public class FurnaceSmeltEvent extends Event implements Cancellable {
     public void setCancelled(boolean cancel) {
         this.cancelled = cancel;
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }

src/main/java/org/bukkit/event/inventory/InventoryListener.java

@@ -5,6 +5,7 @@ import org.bukkit.event.Listener;
 /**
  * Handles all events thrown in relation to Blocks
  */
+@Deprecated
 public class InventoryListener implements Listener {
     public InventoryListener() {}