- Added auto-detection scheme for r_vanillatrans

It now works the following way:
(0) - Force off (ZDoom defaults)
(1) - Force on (Doom defaults)
(2) - Auto off (Prefer ZDoom defaults - if DEHACKED is detected with no ZSCRIPT it will turn on) (default)
(3) - Auto on (Prefer Doom defaults - if DECORATE is detected with no ZSCRIPT it will turn off)

src/d_main.cpp

@@ -116,6 +116,7 @@
 #include "r_utility.h"
 #include "vm.h"
 #include "types.h"
+#include "r_data/r_vanillatrans.h"
 
 EXTERN_CVAR(Bool, hud_althud)
 void DrawHUD();
@@ -2606,6 +2607,9 @@ void D_DoomMain (void)
 			D_CheckNetGame ();
 		}
 
+		// [SP] Force vanilla transparency auto-detection to re-detect our game lumps now
+		UpdateVanillaTransparency();
+
 		// [RH] Lock any cvars that should be locked now that we're
 		// about to begin the game.
 		FBaseCVar::EnableNoSet ();