Make content tree work for unsupported browsers

1) Modify the tree view so when you open a particular page in context, its children are also displayed open.
2) Use the href fallback on the expando-s so that if a user doesn't have Javascript enabled, or they are using a browser that doesn't support XMR, clicking on an expando will reload the page with that part of the heirarchy open.
3) Do something similar for closing an expando.

Don't worry about keeping a running track of everything that is open or closed - just open whatever one they asked for at that moment (if they want it to be fully functional, they should turn JS on).