This reverts commit 0928112a.

 - correct a gyro variable type, and add magnetometer values to ScaledIMU messages.

is executed at any time if triplet as valid yaw waypoint

Add MPC_YAW_MODE option for heading along trajectory, which will be the same as
option 0 (heading towards target) if trajectory is straight line

A line was too long, shrunk it

The Pixhack v3 comes with an external IST8310 in the GPS.

It's used further down again.

- use the orb topic safety to check the safety state, because the actual
  safety state can come from the IO
- fix initialization if circuit breaker is set

FlightTaskAuto: move generation of the the internal waypoints to FlightTaskAuto such that they are available to all derived classes.
Change logic to update the internal triplets only when the navigator triplets have changed or when the vehicle state has changed.

-add FlightTaskAutoMapper that handles the different types of waypoint and
generates setpoints for all types except of position and loiter
- FlightTaskAutoLine generates the setpoint types position and loiter if
the flight between waypoint is a straight line