Changes to static file serving

- /static/custom.css is now located at /config/custom.css
- /static/avatars/ is now located at /config/avatars/
- The redirect script now redirects all room URIs, not just the root
  path. For example, if you are running a server on localhost port 8000,
  visiting http://localhost:8000/teambuilder will now take you to the
  teambuilder. This works for any room.