Update offboard control uorb topic

Work towards supporting the new external setpoint mavlink messages
check sysid and compid for external setpoint
uorb offboard control topic: add force sp flag

The flag has the same meaning as bit 10 of type_mask in
MAVLINK_MSG_ID_LOCAL_NED_POSITION_SETPOINT_EXTERNAL
parsing of MAVLINK_MSG_ID_LOCAL_NED_POSITION_SETPOINT_EXTERNAL
Merge remote-tracking branch 'upstream/master' into offboard2_externalsetpointmessages

Conflicts:
	src/modules/commander/commander.cpp
WIP, change uorb offboard control sp topic
Merge remote-tracking branch 'upstream/master' into offboard2_externalsetpointmessages

Conflicts:
	src/modules/navigator/offboard.cpp
fix merge of mavlink submodule
remove comment
fix merge errors in offboard.cpp
Merge remote-tracking branch 'upstream/master' into offboard2_externalsetpointmessages
vehicle command: add latest guided commands
commander: handle VEHICLE_CMD_NAV_GUIDED_ENABLE
mavlink: external setpoint feed trough functionality
add parsing of external attitude message
Merge remote-tracking branch 'upstream/master' into offboard2_externalsetpointmessages
mavlink external sp: accept 0 sysid and compid
mavlink receiver: fix copy paste error
once offboard is set by mavlink command ignore RC mode
external attitude sp: set timestamp