See discussion here:
https://github.com/ArduPilot/ardupilot/issues/7331
we were getting some uninitialised variables. While it only showed up in
AP_SbusOut, it means we can't be sure it won't happen on other objects,
so safest to remove the approach
Thanks to assistance from Lucas, Peter and Francisco
ahrs should be a reference to DummyVehicle::ahrs, otherwise it will
act on a different object.
This also corrects the member initialization order: only pass a copy
or reference of an object to a constructor if it has already been
initialized.
Peter Barker
Dylan Herman
Andrew Tridgell
Lucas De Marchi
Randy Mackay
squilter