"posmod" is the integer version of "fposmod". We do not need a "mod" because of the % operator.
I changed the default arg names from "x" and "y" to "a" and "b" because they are not coordinates. I also changed pow's arg names to "base" and "exp". Also, I reorganized the code in the VS built-in funcs switch statement.
This allows more consistency in the manner we include core headers,
where previously there would be a mix of absolute, relative and
include path-dependent includes.
Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
