Shifted the calculation of the theta_max cone opening for the pseudo-ellipse outside of all loops.
This is infrastructure change for potentially eliminating all of the looping for the PCS numeric
integration in the future. It however slightly speeds up the pseudo-ellipse frame order model.
Using 500 target function calls in the profiling_pseudo_ellipse.py script in
test_suite/shared_data/frame_order/timings/, the time spent in the pcs_pivot_motion_full_qrint()
function decreases from 20.849 to 20.719 seconds.
