[Bakery-main] App_WithDoc::on_document_modified

[Jamie W. <ja...@sp...>]

So after a bit of hair-pulling I noticed that the view wasn't being updated
when the document changed, which seemed to be a suboptimal instance of the
MVC pattern :-)

I added a call to view.load_from_document() to my App's
on_document_modified method, and everything was good again.  However I'm
wondering why this isn't already done in the base classes.  Document gets
told what the View is already, during App::init_create_document.

Using bakery-2.0 as shipped with Debian unstable and Ubuntu Warty.