Renaming of a registered user now happens without requiring a reconnect

If a registered user's name is changed while he/she is connected, the change is broadcast to all users on the server. The renaming will also be shown in each user's log, as seen below:

**Log screenshot**
![Screenshot](https://cloud.githubusercontent.com/assets/110883/2688377/13b05226-c299-11e3-9b78-d7f860805cf8.png)