Change: include fmt.h C++ headers in stdafx.h

This to prevent compilation issues between runs with and without precompiled
headers. Also remove the headers from the rest of the code base as they are
not needed there anymore, although they do relatively little harm.

src/core/kdtree.hpp

@@ -11,8 +11,6 @@
 #define KDTREE_HPP
 
 #include "../stdafx.h"
-#include <vector>
-#include <limits>
 
 /**
  * K-dimensional tree, specialised for 2-dimensional space.

src/core/math_func.hpp

@@ -10,8 +10,6 @@
 #ifndef MATH_FUNC_HPP
 #define MATH_FUNC_HPP
 
-#include <limits>
-#include <type_traits>
 
 /**
  * Returns the absolute value of (scalar) variable.

src/core/overflowsafe_type.hpp

@@ -12,7 +12,6 @@
 
 #include "math_func.hpp"
 
-#include <limits>
 
 #ifdef __has_builtin
 #	if __has_builtin(__builtin_add_overflow) && __has_builtin(__builtin_sub_overflow) && __has_builtin(__builtin_mul_overflow)

src/core/smallvec_type.hpp

@@ -11,7 +11,6 @@
 #define SMALLVEC_TYPE_HPP
 
 #include "mem_func.hpp"
-#include <vector>
 
 /**
  * Helper function to append an item to a vector if it is not already contained