cookie.js when setValue‘s value parameter is false delete entry

lib/scripts/cookie.js

@@ -22,8 +22,13 @@ var DokuCookie = {
         var text = [],
             _this = this;
         this.init();
-        val = val + "";
-        this.data[key] = val;
+        if (val === false){
+            delete this.data[key];
+        }else{
+            val = val + "";
+            this.data[key] = val;
+        }
+
 
         //save the whole data array
         jQuery.each(_this.data, function (key, val) {
@@ -42,7 +47,7 @@ var DokuCookie = {
      */
     getValue: function(key, def){
         this.init();
-        return key in this.data ? this.data[key] : def;
+        return this.data.hasOwnProperty(key) ? this.data[key] : def;
     },
 
     /**