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

src/main/java/org/bukkit/event/block/BlockFromToEvent.java

@@ -3,6 +3,7 @@ package org.bukkit.event.block;
 import org.bukkit.block.Block;
 import org.bukkit.block.BlockFace;
 import org.bukkit.event.Cancellable;
+import org.bukkit.event.HandlerList;
 
 /**
  * Represents events with a source block and a destination block, currently only applies to liquid (lava and water).
@@ -11,6 +12,7 @@ import org.bukkit.event.Cancellable;
  */
 @SuppressWarnings("serial")
 public class BlockFromToEvent extends BlockEvent implements Cancellable {
+    private static final HandlerList handlers = new HandlerList();
     protected Block to;
     protected BlockFace face;
     protected boolean cancel;
@@ -49,4 +51,13 @@ public class BlockFromToEvent extends BlockEvent implements Cancellable {
     public void setCancelled(boolean cancel) {
         this.cancel = cancel;
     }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
 }