This allows proper dimensions in the stock menus and should make menu layout for mods a lot easier because coordinates are more predictable than with the clean factors.
The feature is opt-in for custom content. As long as only stock elements are used, the menu will be able to switch between both on its own, but as soon as custom classes or custom elements are used, the virtual size must be declared explicitly, defaulting to clean scaling.
Steps to reproduce:
1. Load game.
2. Press any key to bring up the main menu.
3. Move the mouse anywhere out of the menu entries.
4. Press Down arrow.
Expected result: the menu cursor sound is played, the first menu element is selected.
Actual result: the menu cursor sound is played, no menu element is selected.
Repeated Down arrow pressing doesn't give any result, either.
If on step 4 Up arrow is pressed, the last element in the menu is selected.
