HUD display issues

There are a couple of display issues in HUD (augmented reality) mode:

- The destination pin sometimes is not visible, even though it should be. This happens mostly when the user is moving and the direction of travel is determined by the GPS.
- The destination pin does not align with the arrow indicating the direction of travel.
- In landscape mode, the arrow and destination pin only take up half the screen and the distance readout takes up the other half. In this case, the arrow and destination pin have to be centred / be allowed to use the full screen. The distance readout should be placed below the direction arrow, as in portrait mode.

This affects only experimental mode.