Create geometric display calibration file for projection onto a sphere.
CAUTION: This function isn't properly implemented yet and will likely
not work for you as expected. Stay tuned...
This is just a wrapper around
DisplayUndistortionHalfCylinder() which
does the actual work for both half-cylindrical and half-spherical
projection screens.
Psychtoolbox/PsychGLImageProcessing/DisplayUndistortionSphere.m