This adds new parameters Q_TAILSIT_MASK and Q_TAILSIT_MASKCH. These
parameters allow a user to use the tailsitter capabilities of a 3D
plane to teach themselves to prop-hang.
It works by allowing the user to setup a switch on their transmitter
to enable manual pass-thru of a set of the input channels to outputs
when in tailsitter hover. The user can then use that switch to allow
learning of hover control in a 3D plane one channel (or two channels)
at a time.
this allows the user to control tailsitters either in body frame (like
a plane) or in earth frame (like a multicopter). This is useful for
people wanting to learn to fly prop-hang on 3D planes
use both roll and pitch to trigger completion of transition. This
copes with situations where the plane has managed to get itself rolled
over far enough that it can't recover into hover
Andrew Tridgell