Fix save int/string error for id

source/app.d

@@ -117,7 +117,8 @@ void Save(ref TreeView tree){
 		TreeIter it = new TreeIter();
 		store.getIterFirst(it);//TODO: fail if first is null
 		do{
-			for(int i=0 ; i<store.getNColumns() ; i++){
+			std.stdio.write("\t",store.getValueInt(it, 0));
+			foreach(i ; 1..store.getNColumns()){
 				std.stdio.write("\t",store.getValueString(it, i));
 			}
 			writeln();