included negative scores in confirmation checks

Author: honzi

repo.js

@@ -67,7 +67,7 @@ function repo_init(){
     core_repo_init({
       'beforeunload': {
         'todo': function(event){
-            if(score > 0){
+            if(score !== 0){
                 core_escape(true);
                 event.preventDefault();
             }