overzealous elimination of xml parsing

re-merge viewer-public.  has a rough edge or two, but this is closer to the snowglobe2.1 and viewer2.2 code, and beats people re-applying their viewer-public changes piecemeal while waiting for this to land.

It's not loaded each time the side bar is opened - only at login - when it did not persist, the change to the URL that was lost after a restart.