Opening a menu item in a new tab 

There currently is some support for opening menu in a new tab. 
It needs to be added to the x-data, but the default x-data does not include this option. 

This was probably supported earlier? 
Should we include this in the x-data?
Having a global options for this is maybe better, I see this as allways open in new menu or not. 
Having them on each individual one is not something that is used. 