- changed FraggleScript setup so that the MapLoader does not use the global level variable anymore.

This involves passing the level explicitly to many functions. What was done here may seem a bit excessive but at least it covers everything.
Most importantly, the global ActiveThinker pointer has been moved into FLevelLocals and is now getting tracked properly by the level without using dangerous assumptions about how the game organizes its data.

src/p_setup.cpp

@@ -486,7 +486,7 @@ void P_SetupLevel(const char *lumpname, int position, bool newGame)
 		}
 	}
 
-	T_PreprocessScripts();        // preprocess FraggleScript scripts
+	T_PreprocessScripts(&level);        // preprocess FraggleScript scripts
 
 	// build subsector connect matrix
 	//	UNUSED P_ConnectSubsectors ();