Fixed a problem when connecting to multiple servers..

* TODO list is now maintained on GITHUB
https://github.com/matty-r/urChat/issues
* Fixed communication with multiple servers - BufferedReader and
BufferedWriter of the connection class were static methods. This was a
piece that hadn't been changed over during the transition to enable
multiple server connections.
* Improved the handling of the TabbedMouseListener, it finds out the
appropriate class of the selected tab and carries out the correct
method. This will stop things with the same name closing incorrectly.