js: decoding of information

--

* src/Helpers.js: This additional escape should 'repair' special
  characters like spaces in filenames. In the strange world of
  encoding there is little hope that this captures all cases, or
  that it will never fail to return some value, let alone meaningful.
  In my test cases it worked.

lang/js/src/Helpers.js

@@ -116,7 +116,7 @@ export function isLongId (value){
 export function decode (property){
     if (typeof property === 'string'){
         try {
-            return decodeURIComponent(escape(property));
+            return decodeURIComponent(escape(unescape(property)));
         }
         catch (error){
             if (error instanceof URIError) {