Fix a bug in choosing the plugin name for MassiveCommand and add contains entity to WorldExceptionSet.

src/com/massivecraft/massivecore/MassiveCoreEngineCommandRegistration.java

@@ -109,8 +109,8 @@ public class MassiveCoreEngineCommandRegistration extends EngineAbstract
 			MassiveCoreBukkitCommand command = new MassiveCoreBukkitCommand(name, target);
 			
 			// ... and finally register it.
-			Plugin plugin = massiveCurrent.getRegisteredPlugin();
-			String pluginName = plugin != null ? plugin.getName() : "MassiveCore";
+			Plugin plugin = command.getPlugin();
+			String pluginName = (plugin != null ? plugin.getName() : "MassiveCore");
 			simpleCommandMap.register(pluginName, command);
 		}
 		

src/com/massivecraft/massivecore/collections/WorldExceptionSet.java

@@ -1,6 +1,7 @@
 package com.massivecraft.massivecore.collections;
 
 import org.bukkit.World;
+import org.bukkit.entity.Entity;
 
 import com.massivecraft.massivecore.CaseInsensitiveComparator;
 
@@ -29,4 +30,9 @@ public class WorldExceptionSet
 		return this.contains(world.getName());
 	}
 	
+	public boolean contains(Entity entity)
+	{
+		return this.contains(entity.getWorld());
+	}
+
 }