Previously, it was kind of a mess. In different places it was using `char`, `short` and `int`.
The changed properties are flags that are operated upon using bit operations. Therefore, the integer type should be unsigned. Since we only use 2 bits of these flags, `uint8_t` is large enough.
Especially note the change I had to make in `RNA_define.h` to make this work.
Reviewers: campbellbarton
Differential Revision: https://developer.blender.org/D8844
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
