master
AP_Compass: add an init method to SITL::SIM
AP_Compass: guard probing external IIS2MDC with new define
AP_Compass: reserve the sensor ID that was used for LIS2MDL
AP_Compass: all backends take a generic Device rather than an I2CDevice
AP_Compass: provide base class implementation for AP_Compass_Backend::read
AP_Compass: make compass instance number part of AP_Compass_Backend
AP_Compass: MAG_CAL: only autoreboot if calibration succeeds
AP_Compass: drop CAN log message calls
AP_Compass: move logging of MAG message into AP_Compass
AP_Compass: reset MMC3416 before WHOAMI read to fix intermittent detection
AP_Compass: rotate the simulated compass by SIM_BRD_TRIM
AP_Compass: add AP_COMPASS_IIS2MDC_EXTERNAL_BUS_PROBING_ENABLED
AP_Compass: Change the maximum and minimum values of the type to named constants
AP_Compass: use switch statement in failed() method
AP_Compass: specify floating point constants
AP_Compass: use get_roll_deg in place of degrees(get_roll_rad) etc.
AP_Compass: remove use of AP_AHRS from most headers
AP_Compass: update MAG message descriptions