AP_NavEKF: fixed log replay code

also added BARO and ARSP messages
AP_Baro: added alternative setHIL interface

uses pressure and temperature for better log replay
RC_Channel: fixed comment on enable_aux_servos()

thanks to Mike McCauley for spotting
AP_Airspeed: added setHIL() method

useful for log playback
AP_HAL_FLYMAPLE RCOutput.cpp: enable_ch no longer resets servo

FLYMAPLERCOutput::enable_ch incorrectly reset the servo to 0, which caused
servo twitching once per second when RC_Channel_aux::enable_aux_servos
enabled each channel.