Move returning to editor to end of frame

This fixes horizontal and vertical warp backgrounds not resetting, and
also a bunch of other 1-frame glitches, most noticeably cutscene bars
and fadeouts.

This adds a new variable shouldreturntoeditor to Game to signal whether
or not it should return to editor at the end of the frame.

desktop_version/src/Game.cpp

@@ -375,6 +375,10 @@ void Game::init(void)
     fadetolab = false;
     fadetolabdelay = 0;
 
+#if !defined(NO_CUSTOM_LEVELS)
+    shouldreturntoeditor = false;
+#endif
+
     /* Terry's Patrons... */
     superpatrons.push_back("Anders Ekermo");
     superpatrons.push_back("Andreas K|mper");

desktop_version/src/Game.h

@@ -388,6 +388,7 @@ public:
 
 #if !defined(NO_CUSTOM_LEVELS)
     void returntoeditor();
+    bool shouldreturntoeditor;
 #endif
 };
 

desktop_version/src/Input.cpp

@@ -1537,7 +1537,7 @@ void gameinput()
                    game.activeactivity = -1;
                }
             }else{
-                game.returntoeditor();
+                game.shouldreturntoeditor = true;
             }
         }
     }

desktop_version/src/Logic.cpp

@@ -1380,4 +1380,12 @@ void gamelogic()
 
     if (game.teleport_to_new_area)
         script.teleport();
+
+#if !defined(NO_CUSTOM_LEVELS)
+    if (game.shouldreturntoeditor)
+    {
+        game.shouldreturntoeditor = false;
+        game.returntoeditor();
+    }
+#endif
 }