Display current thrust level of all players in the TrackWidget

[Henrik Heimbuerger]

Display the current thrust level of all players in the TrackWidget.

Design:

• the gauges are drawn in the upper left corner of the TrackWidget (could later be moved into a separate view)
• the gauges consist of a black rectangle with the player's name below
• the gauges are filled with a red->green gradient according to the current thrust

This is mostly for debugging the input device integration and might be removed for the final version of the application.

[SVN]

New commit by hheimbuerger (revision [190]):
[Fix for ticket #55] Implemented thrust gauges to be shown on the TrackWidget.

The upper left corner of the TrackWidget now displays thrust gauges. These are currently filled with data directly from all available input devices and not from the players as it should be. Also, the devices are polled at the time of drawing instead of the polling being triggered by the RaceEngine.

To make this temporarily work, the InputDeviceManager now calls the DeviceController's initialize() method when a new device is added. This is just a hack and has to be removed because it can cause devices to be initialized mulitple times and initializes devices long before they will be used in the final version (the initialization should probably take place when the race is started).
Additionally, the KeyboardDevice? now returns a fixed signal when polled (always 50% thrust) for testing.

Besides, the TrackWidget now uses a customized font for displaying player (currently: device) names and the frame counter.

[Henrik Heimbuerger]

Batch moved MS3 (input device/technology integration) to MS1 (first working version).