Jump to correct private chat via notification

[weberpatr]

When you get a new private message and want to get there via the notification icon, you just get to the messages page, instead of the announced new message (as many would expect). Maybe there is a possibility to change that.

[mischkadb]

The PNs are now sorted by timestamp of messages, sorted by latest. While it does not exactly open the message from the notification it will always load the latest message tab. It's probably good enough until I revamp the notifications.