Split FoxGame into a JFrame and JPanel part

FoxGame is still the JFrame.
FoxGameGuiPanel is now a separate gui component that is used in
FoxGame but may easily be used by other applications.
Put MockOutputStream in its own class
Added test event sources
Added OutputArea
Improved interactive testing

- DebuggingClient uses Proxy
- Added PlayerPanel
- Added TestFoxGame, a test application with monitor + player interface.
- Oops, forgot to add AbstractEventSource
MonitorSetup aborts more gracefully