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
After this commit it should be possible to share the same deformation
formulas that are used in the Elastic Deform brush with other areas of
Blender such as Grease Pencil or proportional editing.
This also removes a lot of code from sculpt.c that is not direclty
related to sculpting.
Reviewed By: jbakker
Differential Revision: https://developer.blender.org/D6281
Sebastian Parborg
Jacques Lucke
Pablo Dobarro