Plane: prepare for 3.1.0-beta2
AP_Airspeed: added HIL support
Plane: added airspeed simulation in HIL
Replay: fixed build
CPUInfo: fixed build
VARTest: fixed build
SITL: added SIM_SONAR_SCALE parameter

used for simulating different kinds of rangefinders
SITL: better rangefinder simulation

able to handle a wider range, and takes account of attitude
Merge branch 'master' of https://github.com/diydrones/ardupilot into uavcan
renamed px4mix target
AP_MotorsPX4: implement get_motors_mask()
AP_MotorsPX4: integrated mixer loading, added configuration by params
rc.APM: removed debug stuff
AP_MotorsPX4: publish control commands even when idle to prevent PX4IO failsafe