xfwm: support for 2d pagers

[Paramjit Oberoi]

> >*  Just one wheel scrolls vertically; hotkey+wheel scrolls horizontally
> >   (or the other way around, depending on your inclincation).  I guess
> >   there can be two config vars - vert_scroll_modifier &
> >   horz_scroll_modifier, and one of them would be allowed to be null.
> Yes, this is what I meant. And "wrap_layout" would control if scrolling 
> ends at the edges or wraps.
> 
> To prevent update surprises, we must still scroll left and right when 
> the normal, i.e. vertical wheel is turned. As I see no way to check from 

Ok.

> >PS: All this assumes that the current move to next/prev workspace
> >functionality is obsolete, which I am not completely convinced of.
> Not necessarily. Arguably "wrap layout" could be overloaded to mean: 
> Stop at the first/last workspace. I heard someone saying, he just helds 

There is existing option to control that: wrap_workspaces

-param