- This should improve pointing at ROI and replaces #11172
- Remove unused member variable as per review suggestion
- declare Mode::AutoYaw::roi_yaw() as const
This makes us look like Rover and Plane in terms of namespacing for the
Mode classes, and removes a wart where we #include mode.h in the middle
of the Mode class.
This was done mechanically for the most part.
I've had to remove the convenience reference for ap as part of this.