Added alias for trace clear

BauSystem_Main/src/de/steamwar/bausystem/features/tracer/TraceCommand.java

@@ -134,6 +134,7 @@ public class TraceCommand extends SWCommand {
         BauSystem.MESSAGE.send("TRACE_MESSAGE_HIDE", player);
     }
 
+    @Register(value = "delete")
     @Register(value = "clear")
     public void clear(@Validator Player player) {
         TraceManager.instance.clear(Region.getRegion(player.getLocation()));