Add CMake build and cross-platform cleanup

Game/pch.h

@@ -1,6 +1,6 @@
 #pragma once
 //ML Detection Extension
-#ifdef _DEBUG
+#if defined(_MSC_VER) && defined(_DEBUG)
 #define _CRTDBG_MAP_ALLOC
 #include <cstdlib>
 #include <crtdbg.h>
@@ -8,13 +8,18 @@
 #define new DEBUG_NEW
 #endif
 // SDL and OpenGL Includes
+#if defined(_MSC_VER)
 #pragma warning(disable : 26812)
 #pragma warning(disable : 4820)
+#endif
 #include <SDL.h>
 #include <SDL_opengl.h>
 #include <SDL_ttf.h>
 #include <SDL_mixer.h>
 #include <SDL_image.h>
 
+#if defined(_MSC_VER)
 #pragma warning(default : 26812)
+#pragma warning(default : 4820)
+#endif
 #include "structs.h"