Don't process music, fades, or timer when unfocused

This fixes being able to make music fully fade in (or out) by unfocusing
the game, or making the fade bars fully fade in (or out) by unfocusing
the game, or racking up the timer while the game is unfocused.

desktop_version/src/main.cpp

@@ -728,7 +728,9 @@ static void focused_begin(void)
 
 static void focused_end(void)
 {
-    /* no-op. */
+    game.gameclock();
+    music.processmusic();
+    graphics.processfade();
 }
 
 static enum LoopCode loop_end(void)
@@ -789,9 +791,5 @@ static enum LoopCode loop_end(void)
         gameScreen.ResizeScreen(-1, -1);
     }
 
-    music.processmusic();
-    graphics.processfade();
-    game.gameclock();
-
     return Loop_continue;
 }