Expose newgamecustom menu and submenu index to CON (read-only).
Addresses #21 (closed).
The idea is to allow displaying of tooltips and other graphics on newgamecustom entries, based on the current menu selection. An example would be a small description at the bottom of the screen for the Bonus Missions in Ion Fury, or the Chapter Select.
With the standard newgame menu this is already possible through ud.m_volume_number
(introduced in ad85f45f). This merge request would bring the same functionality to the newgamecustom
menu.