Fix aggressive glitchrunner hardreset causing issues quitting to menu

This fixes the bug where in glitchrunner mode, quitting to the menu
would always put you back at the play menu on the first option, instead
of the menu you entered the game from.

The problem is the script.hardreset() that gets called before the game
actually quits to the menu, so when Game::quittomenu() gets called to
quit to the menu, all the variables that keep track of whether you're in
a certain gamemode, such as game.insecretlab and map.custommode, all get
prematurely reset before that function can read them and put you back to
the correct menu.

The solution here is to simply reset only what's needed when quitting to
the menu. Specifically, in order for credits warp to work,
script.running needs to be set to false and all the text boxes need to
be removed. Text boxes need to be gone so the "- Press ACTION to advance
text -" prompt will stay up without a text box, enabling the player to
increment the gamestate at will by pressing ACTION, and the script needs
to stop running so further text boxes don't spawn in.

Fixes #389.

desktop_version/src/Input.cpp

@@ -2100,7 +2100,8 @@ void mapinput()
         else
         {
             // Produces more glitchiness! Necessary for credits warp to work.
-            script.hardreset();
+            script.running = false;
+            graphics.textbox.clear();
 
             game.state = 80;
             game.statedelay = 0;