Return 404 if the local site name doesn't exist.
Review Request #2072 — Created Jan. 27, 2011 and submitted
Return 404 if the local site name doesn't exist. I noticed the other day that accessing the dashboard with a local site name that didn't exist showed me a dashboard page. This was happening because we used get_object_or_none for the local site in a lot of places, which meant that said views were showing the root data instead of 404.
Tested views manually and ran unit tests.
