Change gamestate ints to their enum names

This is to make it easier to read, so I don't have to reference Enums.h
if I want to know what they are referring to.

desktop_version/src/editor.cpp

@@ -3448,7 +3448,7 @@ void editorlogic()
         //Return to game
         map.nexttowercolour();
         map.colstate = 10;
-        game.gamestate = 1;
+        game.gamestate = TITLEMODE;
         graphics.fademode = 4;
         music.haltdasmusik();
         music.play(6);