AP_HAL_Linux: enable output for PCA9685 PWM in NavioRCOuput
AP_HAL_Linux: added LinuxSPIUARTDriver that can handle SPI-driven Ublox
AP_HAL_Linux: external GPS fixed
AP_Compass: added AK8963 support
Rover: added AK8963 support
Plane: added AK8963 support
Copter: added AK8963 support
Antenna: added AK8963 support
AP_HAL: changed default compass for Navio
AP_InertialSensor: prevented MPU9250 from disabling I2C slaves