Remove global args from Game

I've decided to call dwgfx/game/map/obj/key/help/music the "global args".
Because they're essentially global variables that are being passed
around in args.

This commit removes global args from all functions on the Game class,
and deals with updating the callsites of said functions accordingly. It
also renames all usages of 'dwgfx' in Game.cpp to 'graphics', since the
global variable is called 'graphics' now.

Interesting to note, I was removing the class defines from Game.h, but
it turns out that Graphics.h depends on the mapclass and entityclass
defines from Game.h. And also Graphics.h spelled mapclass wrong (it
forgot the "class") so I just decided to use that existing line instead.
This is only temporary and after all is said and done, at the end of
this pull request those class defines will be gone.

desktop_version/src/main.cpp

@@ -191,7 +191,7 @@ int main(int argc, char *argv[])
     map.bypos = map.ypos / 2;
 
     //Moved screensetting init here from main menu V2.1
-    game.loadstats(map, graphics);
+    game.loadstats();
     if (game.skipfakeload)
         game.gamestate = TITLEMODE;
 		if(game.usingmmmmmm==0) music.usingmmmmmm=false;
@@ -500,7 +500,7 @@ int main(int argc, char *argv[])
         if (game.savemystats)
         {
             game.savemystats = false;
-            game.savestats(map, graphics);
+            game.savestats();
         }
 
         //Mute button
@@ -565,7 +565,7 @@ int main(int argc, char *argv[])
     //SDL_FreeSurface( gameScreen );
 
     //Quit SDL
-    game.savestats(map, graphics);
+    game.savestats();
     NETWORK_shutdown();
     SDL_Quit();
     FILESYSTEM_deinit();