Merged with master

makefiles/config_px4fmu_default.mk

nuttx/configs/px4fmu/nsh/defconfig

src/drivers/device/i2c.h

src/drivers/md25/md25.cpp

src/drivers/md25/md25.hpp

src/drivers/md25/md25_main.cpp

src/drivers/md25/module.mk

src/modules/controllib/fixedwing.cpp

src/modules/controllib/fixedwing.hpp

src/modules/fixedwing_backside/params.c

src/modules/mavlink/mavlink_receiver.c