message: Fix minus sign in picking example camera position
  Fix issue in the glium repository. I couldn't replicate the subtract with overflow component of the issue on ubuntu though.
diff: @@ -102,7 +102,7 @@ fn main() {
  ).unwrap();
  let mut camera = support::camera::CameraState::new();
  - camera.set_position((0.0, 0.0, 1.5));
  + camera.set_position((0.0, 0.0, -1.5));
  camera.set_direction((0.0, 0.0, 1.0));
  //id's must be unique and != 0
  