Fixed backup / restore, unified file name generation.

js/backup_restore.js

@@ -168,9 +168,6 @@ function configuration_backup(callback) {
 
         var filename = generateFilename(prefix, suffix);
 
-        // replace invalid filesystem characters
-        now = now.replace(new RegExp(':', 'g'), '_');
-
         // create or load the file
         chrome.fileSystem.chooseEntry({type: 'saveFile', suggestedName: filename, accepts: [{ extensions: [suffix] }]}, function (fileEntry) {
             if (chrome.runtime.lastError) {