Making it possible to drag addresses from the sidebar to the addressing widget.
Currently attempting to do this fails because nsDragAndDrop is not defined.
(And logged in the error console, so I guess nobody has tried it...)
abResultsPaneObserver from abDragDrop.js is also needed.
Created attachment 584230 [details] [diff] [review]
D'oh, I thought I'd clicked the checkbox...
Pushed changeset 2a9cca621e7c to comm-central.