Support for Undo

[Erick Pérez Castellanos <erick red gmail com>]

Hi:
I've been looking to this
bug:https://bugzilla.gnome.org/show_bug.cgi?id=657975 and after seeing
the discussion with the folks devs, I think the final choice is to wait,
if the user doesn't press Undo, then commit to libfoklks the operation
right ?.
Well, in that case, I say, why not use the same pattern for linking.