Better handling of Kinect connection/disconnection (...)

- Added a SensorChanged event, fired on all Kinect status events.
- A last null BitmapSource is thrown when the Sensor goes dark, effectively blanking the Image
- Now showing Kinect status information, bound in the ViewModel. Planning on making a KinectSensorInformation object.
- ViewModel will bind itself to the Model, here, the Kinect through the KinectSensorController.