Compute a quaternion from cone and clock angles. 
   The sail rotation is constrained to the y and z axes. This is appropriate
   when the attitude control is limited, i.e. a control boom.

   The cone angle is the angle between the sail and sun vectors and the clock 
   angle is in the sun normal plane measured from the intersection with the 
   orbit plane. In a frame defined with the x axis towards the sun, 
   the y axis along the cross product of the orbit normal and sun vector,
   and the third vector completing the set, the clock angle is measured from
   the y axis. The unit vector is in the same frame as r, v, and s.

   Requires the position, velocity and sun vectors. The latter is a unit
   vector. You can input multiple sets and the function will return
   a 3-by-n vector.

   See ConeClockToU for a demo showing the unit vectors for a circular
   orbit around the sun. See also QSail which uses the same frame.

   Since version 7.
   q = ConeClockToQConstrained( cone, clock, r, v, s )

   cone          (1,:) Cone angle (rad)
   clock         (1,:) Clock angle (rad)
   r             (3,:) Orbit vector
   v             (3,:) Velocity vector
   s             (3,:) Sun unit vector (from sc to sun)

   q             (3,n) Quaternions



Common: Quaternion/Mat2Q
Common: Transform/Eul2Mat
Math: Linear/Cross
Math: Linear/Unit