revert the current alt behaviour

[hooke007]

Holding alt while activating an item should prevent closing the menu (this is just a guideline, not all menus behave this way).

I must miss sth that I don't why it only works for some independent menus.

For example, in the previous versions, alt work for the any items written in the input.conf
Now I have to build different menus scripts to make it work.

[tomasklaen]

The note that it only works for some menus is there because since the latest menu API rework, this now needs to be implemented on per menu basis.

But all uosc menus should have it built in. The fact it doesn't work on main menu is a bug. Gimme a sec.