Now caches the world properties before unloading the world in order to prevent NPE on unload then load. Really fixes #947.

src/main/java/com/onarandombox/MultiverseCore/MVWorld.java

@@ -373,17 +373,6 @@ public class MVWorld implements MultiverseWorld {
         };
     }
 
-    /**
-     * This prepares the MVWorld for unloading.
-     */
-    public void tearDown() {
-        try {
-            this.props.tearDown();
-        } catch (IllegalStateException e) {
-            // do nothing
-        }
-    }
-
     /**
      * Initializes permissions.
      */

src/main/java/com/onarandombox/MultiverseCore/WorldProperties.java

@@ -297,7 +297,7 @@ public class WorldProperties extends SerializationConfig {
     /**
      * This prepares the MVWorld for unloading.
      */
-    public void tearDown() {
+    public void cacheVirtualProperties() {
         try {
             this.buildVPropChanges();
         } catch (IllegalStateException e) {

src/main/java/com/onarandombox/MultiverseCore/utils/WorldManager.java

@@ -311,12 +311,10 @@ public class WorldManager implements MVWorldManager {
     @Override
     public boolean unloadWorld(String name) {
         if (this.worlds.containsKey(name)) {
+            this.worldsFromTheConfig.get(name).cacheVirtualProperties();
             if (this.unloadWorldFromBukkit(name, true)) {
                 this.worlds.remove(name);
                 Logging.info("World '%s' was unloaded from memory.", name);
-
-                this.worldsFromTheConfig.get(name).tearDown();
-
                 return true;
             } else {
                 Logging.warning("World '%s' could not be unloaded. Is it a default world?", name);