Default to the home page if passed an invalid route.
Default to the home page if passed an invalid route.

This fixes the second error seen in #216

Note, this only effects bad urls (#fooabare) that aren't defined
routes. Non-existent issues (e.g. /#issue/foo) are still valid
routes, and so don't trigger the default behavior.

5calls/5calls,5calls/5calls,5calls/5calls,5calls/5calls