do not use precompiled header for setting global compiler definitions and to disable compiler warnings

only 4 of these warnings are still relevant, CMake shall be used to disable them

Compiler definitions:

  NOMINMAX:
    * is already globally defined in SetGlobalCompilerAndLinkerSettings.cmake

  WIN32_LEAN_AND_MEAN:
    * use CMake target_compile_options on relevant targets

Warnings that still occur:

  C4251, C4273, C4275: all related to dllimport / export
    * use CMake target_compile_options on relevant targets

  C4661: no suitable definition provied for explicit template instantiation request
    * triggered in Mesh because of Vector3D in Base - not all functions are defined in header
    * use CMake target_compile_options on relevant targets

Warnings that are Currently not triggered (fix code if they appear again):

  C4005: macro redefinition

  C4244: argument conversion, possible loss of data

  C4267: conversion from size_t to type, possible loss of data

  C4305: truncation from type1 to type2
    * only occurrence disabled in Reader.cpp

  C4522: multiple assignment operator specified

  C5208: unnamed class in typedef name

Obsolete Compiler warnings:

  C4181: not mentioned in Microsoft docs anymore

  C4290: C++ exception specification ignored except to indicate a function is not __declspec(nothrow)
    * throw(optional_type_list)  deprecated in C++17

  C4482: nonstandard extension used: enum 'enumeration' used in qualified name
    * not generated for compilers that support C++11

  C4503: 'identifier': decorated name length exceeded, name was truncated
    * obsolete since Visual Studio 2017

  C4786: not mentioned in Microsoft docs anymore

src/Base/CMakeLists.txt

@@ -340,6 +340,11 @@ endif(FREECAD_USE_PCH)
 
 target_sources(FreeCADBase PRIVATE ${FreeCADBase_SRCS})
 target_link_libraries(FreeCADBase ${FreeCADBase_LIBS})
+
+if (MSVC)
+    target_compile_definitions(FreeCADBase PRIVATE WIN32_LEAN_AND_MEAN)
+endif()
+
 if (FREECAD_WARN_ERROR)
     target_compile_warn_error(FreeCADBase)
 endif()

src/Base/PreCompiled.h

@@ -45,10 +45,6 @@
 
 #ifdef FC_OS_WIN32
 #include <direct.h>
-#define WIN32_LEAN_AND_MEAN
-#ifndef NOMINMAX
-#define NOMINMAX
-#endif
 #include <windows.h>
 #include <crtdbg.h>
 #include <shellapi.h>