ov50 - Not sure all the rotation selections work as intended.

[rgleason]

https://ci.appveyor.com/project/seandepagnier/rotationctrl-pi/builds/22599947/artifacts

It works, but I am not at all sure that
Course
Heading
Wind
Route Up
work as intended..
I assume the rotation of the screen is supposed to be well aligned with the selection, not more than 15 degrees off. If this is true then it is not working as expected, but all the heading buttons do seem to change the screen, just not always as expected.