(js) Add support for XSRF token with downloads

Initial support to download a file from an Ajax query. This allows the
XSRF token to be sent and verified by the server.

UI/WebServerResources/js/Mailer/MailboxController.js

@@ -26,7 +26,6 @@
     vm.markOrUnMarkMessagesAsJunk = markOrUnMarkMessagesAsJunk;
     vm.copySelectedMessages = copySelectedMessages;
     vm.moveSelectedMessages = moveSelectedMessages;
-    vm.saveSelectedMessages = saveSelectedMessages;
     vm.markSelectedMessagesAsFlagged = markSelectedMessagesAsFlagged;
     vm.markSelectedMessagesAsUnread = markSelectedMessagesAsUnread;
     vm.selectAll = selectAll;
@@ -153,12 +152,6 @@
       });
     }
 
-    function saveSelectedMessages() {
-      var selectedMessages = _.filter(vm.selectedFolder.$messages, function(message) { return message.selected; });
-      var selectedUIDs = _.map(selectedMessages, 'uid');
-      window.location.href = ApplicationBaseURL + '/' + vm.selectedFolder.id + '/saveMessages?uid=' + selectedUIDs.join(",");
-    }
-
     function selectAll() {
       var i = 0, length = vm.selectedFolder.$messages.length;
       for (; i < length; i++)