VTOL transition failsafe RTL

msg/vehicle_status.msg

msg/vtol_vehicle_status.msg

src/lib/ecl

src/modules/commander/commander.cpp

src/modules/commander/state_machine_helper.cpp

src/modules/vtol_att_control/vtol_att_control_main.cpp

src/modules/vtol_att_control/vtol_type.cpp

src/modules/vtol_att_control/vtol_type.h