> Normally, `imenu' supports nested menus, when users select the target
> location in steps, like item3 <RET> -> item3.1 <RET> -> ...
>
> What is proposed is to list all the sub-menus together, as an option, so
> that the users can choose, for example, item.3.1 directly, without going
> through parent item3.
Shouldn't each sub-item keep the parent menu item as a prefix?
So a nested menu like
menu1
sub-item1
sub-item2
could be flattened to
menu1 -> sub-item1
menu1 -> sub-item2
Or this should be optional?
