Server-side multiworld support with several improvements overal.

src/main/java/org/dynmap/Event.java

@@ -0,0 +1,26 @@
+package org.dynmap;
+
+import java.util.LinkedList;
+import java.util.List;
+
+public class Event<T> {
+    private List<Listener<T>> listeners = new LinkedList<Listener<T>>();
+    
+    public synchronized void addListener(Listener<T> l) {
+        listeners.add(l);
+    }
+    
+    public synchronized void removeListener(Listener<T> l) {
+        listeners.remove(l);
+    }
+    
+    public synchronized void trigger(T t) {
+        for (Listener<T> l : listeners) {
+            l.triggered(t);
+        }
+    }
+    
+    public interface Listener<T> {
+        void triggered(T t);
+    }
+}