Merge branch 'master' of github.com:PX4/Firmware into cmake-2

NuttX

README.md

src/lib/uavcan

src/modules/mavlink/mavlink_main.cpp

src/modules/uavcan/module.mk

src/modules/uavcan/uavcan_clock.cpp

src/modules/uavcan/uavcan_main.cpp

src/modules/uavcan/uavcan_main.hpp

src/modules/uavcan/uavcan_servers.cpp

src/modules/uavcan/uavcan_servers.hpp