Cut case MAVLINK_MSG_ID_HIL_STATE_QUATERNION content and paste into handle_message_hil_state_quaternion() method.

Cut case MAVLINK_MSG_ID_HIL_OPTICAL_FLOW content and paste into handle_message_hil_optical_flow() method.

Cut case MAVLINK_MSG_ID_DISTANCE_SENSOR content and paste into handle_message_distance_sensor() method.

Cut case MAVLINK_MSG_ID_LANDING_TARGET content and paste into handle_message_landing_target() method.

mission_feasibility_checker: takeoff: add a different log message when there's a takeoff item but it's not the first waypoint

mission_feasibility_checker: takeoff: accept mission when takeoff is not the first item but the previous items are not waypoints

navigator: mission feasibility checker: check for a takeoff waypoint on mission on specific conditions

 - the Jenkins slave now has the gdb server already started in the background

   nARMED is a Digital OUTPUT. GPIO will be set as input while not
   armed HW will have Pull UP. While armed it will be configured
   as a GPIO OUT set LOW.

   This adds an optional default support for HW that does not
   have and external armed indiction.

Mavlink receiver: Move most variable initializations out of the constructor to the variable declarations

by comparing the configuration options that cmake reports
from the cache with the ones from the current build

cleanup nuttx_, _default targets

Move member variable initialization out of the constructor list to variable declarations, format whitespaces/tabs in sf1xx.cpp.

Before if you were above the maximum altitude you could not command to
go down anymore until the position controller had overshoot to under the
maximum altitude again.

 - fixes Coverity CID 328485