Global shortcuts for plasma service

[Michail Vourlakos]

> aha! ok .. so imho this belongs more in kactivitymanagerd (kamd) itself.
>
> i was considering whether or not it makes sense to have different orders of
> activities .. and i don't think it does. activities should probably be
> globally consistent.
>
> where we coordinate all activity related information in kamd. it would
> probably be best if kamd would store the order and coordinate the keyboard
> shortcuts for jumping between those ordered items.
>
>
For the time, I implemented it through the data engine. The data engine 
creates two
global shortcuts to go to next or previous ordered activity