Npc definitions/npc aggressiveness (#169)

Let me know how it works

2006Redone Server/src/redone/util/XStreamUtil.java

@@ -0,0 +1,37 @@
+package redone.util;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import com.thoughtworks.xstream.XStream;
+
+import redone.game.npcs.NPCDefinition;
+
+public class XStreamUtil {
+	
+	private static XStreamUtil instance = new XStreamUtil();
+	private static XStream xStream = new XStream();
+	
+	public static XStreamUtil getInstance() {
+		return instance;
+	}
+        
+    static {
+		xStream.alias("npcDefinition", NPCDefinition.class);
+	}
+
+	public static XStream getXStream() {
+		return xStream;
+	}
+	
+    public static void writeXML(Object object, File file) throws IOException {
+        FileOutputStream out = new FileOutputStream(file);
+        try {
+            xStream.toXML(object, out);
+            out.flush();
+        } finally {
+            out.close();
+        }
+    }
+
+}