Latest: https://github.com/mavlink/c_library_v2/commit/95d4cb3b21130d67b251f323482f1c3fe1ce0c6c

Changes from v2.0 (https://github.com/mavlink/c_library_v2/commit/37d14af47d783eb516959cc10e4cf70d66e927c0) in current PX4/master (9fc1755c)
https://github.com/mavlink/c_library_v2/compare/37d14af47d783eb516959cc10e4cf70d66e927c0...95d4cb3b21130d67b251f323482f1c3fe1ce0c6c

95d4cb3 2018-03-28 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/f29e3302fef08a9df6bd2b2e944f1fbf35637035
f8b4fc9 2018-03-27 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/4accd6c062f6ca79a025f596744fc9cf907acc98
695883f 2018-03-27 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/b4efea1609631683c7b29f85571ba2f34a10116e
1bb9b2c 2018-03-27 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/56e28570a7557e62e95613d7bd13a96e8cf5e02e
68f9957 2018-03-27 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/8cf87fc5afe996604cc4399f21f83c7989ae5d9a
62abc60 2018-03-26 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/17207917a38ad690b3995e168b51bf232094b165
1b0dc47 2018-03-23 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/1d007c59dbe0121b7f2063a8919a44703634a5ef
925ab39 2018-03-21 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/5515533e8e5222aa1794616b124eddcaa040a5b3
f38624f 2018-03-15 PX4BuildBot - autogenerated headers for rev https://github.com/mavlink/mavlink/tree/91a22feb27e718373dd68e6fc57329f13f5e8d8a

This brings in new ROI commands and general sync.

 - update mavlink, cmake_hexagon, uavcan_board_ident to latest

The mavlink message MOUNT_STATUS has been renamed to MOUNT_ORIENTATION.

This changes the Firmware code accordingly.