Some plot area restructuring

Nukkit/src/main/java/com/plotsquared/nukkit/events/PlotClearEvent.java

@@ -36,7 +36,7 @@ public class PlotClearEvent extends PlotEvent implements Cancellable {
      * @return String
      */
     public String getWorld() {
-        return getPlot().getArea().worldname;
+        return getPlot().getWorldName();
     }
 
 

Nukkit/src/main/java/com/plotsquared/nukkit/events/PlotComponentSetEvent.java

@@ -37,7 +37,7 @@ public class PlotComponentSetEvent extends PlotEvent {
      * @return String
      */
     public String getWorld() {
-        return getPlot().getArea().worldname;
+        return getPlot().getWorldName();
     }
 
     /**

Nukkit/src/main/java/com/plotsquared/nukkit/events/PlotDeleteEvent.java

@@ -35,7 +35,7 @@ public class PlotDeleteEvent extends PlotEvent {
      * @return String
      */
     public String getWorld() {
-        return getPlot().getArea().worldname;
+        return getPlot().getWorldName();
     }
 
 }

Nukkit/src/main/java/com/plotsquared/nukkit/util/NukkitEventUtil.java

@@ -90,7 +90,7 @@ public class NukkitEventUtil extends EventUtil {
 
     @Override
     public boolean callMerge(Plot plot, ArrayList<PlotId> plots) {
-        return callEvent(new PlotMergeEvent(NukkitUtil.getWorld(plot.getArea().worldname), plot, plots));
+        return callEvent(new PlotMergeEvent(NukkitUtil.getWorld(plot.getWorldName()), plot, plots));
     }
 
     @Override

Nukkit/src/main/java/com/plotsquared/nukkit/util/NukkitSetupUtils.java

@@ -27,6 +27,11 @@ public class NukkitSetupUtils extends SetupUtils {
         Generator.addGenerator(NukkitHybridGen.class, "PlotSquared", 1);
     }
 
+    @Override
+    public void unload(String world, boolean save) {
+        plugin.getServer().unloadLevel(plugin.getServer().getLevelByName(world), save);
+    }
+
     @Override
     public void updateGenerators() {
         if (!SetupUtils.generators.isEmpty()) {