Change arming transfer to only set the register if the local configuration changed. Move its write operation to the fast rate so that arming / disarming is instantaneous

Kill switch: Fix logic to only trigger on on/off state of switch, not on/undefined. Remove debug output.

multirotor mission feasibility checks:

make sure that the relative altitude of the takeoff waypoint is
at least one meter higher than the acceptance radius of the waypoint.
This makes sure that the takeoff waypoint is not reached before the vehicle
is at least one meter in the air.

quick fix:

Remove throttle non-increase condition for landing since this has lead to
quads falling out of the sky.

QuadRanger airframe

add RC_OUT pin to FMUv4 config