Navigator Update -- full drag and drop

[Geoff Canyon]

You can now drag and drop from Navigator windows to LC stacks, and from
Navigator windows to other Navigator windows. You can:

Drag controls and bookmarks from Navigator to a stack to add and position
controls. (Note, this always duplicates the control even if you're dragging
a control that is already on the target card).

Drag controls and bookmarks from Navigator to another Navigator to add
controls or bookmarks.

Drag cards and groups to copy them from one stack to another.

You can get Navigator here
<https://www.dropbox.com/s/kz3zqi4botzglgq/navigator.zip?dl=1>.

Documentation will be updated over the next day or two.