Plane: fixed mavlink levelling

this was broken by a recent commit (after 2.72 was released)
AP_Compass: fixed the HIL sensors compass

this sets up good compass values for HIL sensors
Rover: use new HIL compass API
Copter: use new HIL compass API
Copter: removed the deprecated HIL sensors interface

must use the new HIL_STATE message now
Plane: use new HIL compass API
Plane: enable compass on all boards by default

if not present, then mag init will fail and it will disable
SITL: use new HIL compass API