The AR Drone currently does not support reading individual parameters
by index.  It also currently seems to always fail to send the
parameter with index 8!

This code works around both of these issues without affecting other
drones by re-requesting the entire parameter set if the drone is an AR
Drone and by reducing the expected number of parameters after 3
retrys.  This should work reliably even if the AR Drone firmware bug
gets fixed someday.
Merge branch 'ardrone_params' into everything