This allows real world cameras to be modeled by specifying the coordinates of a
4th degree polynomial that relates a pixels distance (in mm) from the optical
center on the sensor to the angle (in radians) of the world ray that is
projected onto that pixel.
This is available as part of the panoramic lens type, however it can also be
used to model lens distortions in projective cameras for example.
Differential Revision: https://developer.blender.org/D12691
Remove prefix of filenames that is the same as the folder name. This used
to help when #includes were using individual files, but now they are always
relative to the cycles root directory and so the prefixes are redundant.
For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.