server does not create non-existant pages

Once we thought this was a good idea. Now we leave
it to the client to handle the 404. However, there
have been a few paths (like refreshing a long url)
that can find its way into the server-side create.

Now server side returns 404 in this case too. This
is a sinatra-only issue. Express has always 404'd 
in this case.
reading a default-page doesn't copy it
redirect to welcome-visitors (root)

this improves browsing with lynx and search
engine bots.
minimal server-side rendering doesn't include journal
annotate pages served from plugins
green borders on plugin pages
Merge branch 'master' of github.com:WardCunningham/Smallest-Federated-Wiki