- the big cleanup of the exit cleanup is done!

atterm is gone and only a few system-side functions use atexit.
All game side cleanup is performed in D_DoomMain now.

src/p_setup.cpp

@@ -75,14 +75,12 @@
 #include "i_system.h"
 #include "v_video.h"
 #include "fragglescript/t_script.h"
-#include "atterm.h"
 #include "s_music.h"
 
 extern AActor *SpawnMapThing (int index, FMapThing *mthing, int position);
 
 extern unsigned int R_OldBlend;
 
-static void P_Shutdown ();
 
 //===========================================================================
 //
@@ -572,15 +570,13 @@ void P_SetupLevel(FLevelLocals *Level, int position, bool newGame)
 //
 void P_Init ()
 {
-	atterm(P_Shutdown);
-
 	P_InitEffects ();		// [RH]
 	P_InitTerrainTypes ();
 	P_InitKeyMessages ();
 	R_InitSprites ();
 }
 
-static void P_Shutdown ()
+void P_Shutdown ()
 {
 	for (auto Level : AllLevels())
 	{