This replaces header include guards with `#pragma once`.
A couple of include guards are not removed yet (e.g. `__RNA_TYPES_H__`),
because they are used in other places.
This patch has been generated by P1561 followed by `make format`.
Differential Revision: https://developer.blender.org/D8466
Deformation of subdivision surface modifier was using wrong coordinates
for the coarse mesh: as the modifier flow goes the coordinates are to be
taken from the input array of coordinates.
Jacques Lucke
Campbell Barton
Sergey Sharybin