We have a lot of strings in our templates, but they aren't marked
for translation! As part of the process of making MediaGoblin
translatable we should make all templates marked with the {% trans
%} tag.

`http://jinja.pocoo.org/docs/templates/#i18n <http://jinja.pocoo.org/docs/templates/#i18n>`_

When the user clicks their email validation link, a userid and a
token are sent in the querystring. However, in line 160 of
mediagoblin/auth/views.py, we are redirecting according to the
'username' session variable.

If the user is not logged in, the following traceback ensues:

::

    ----------------------------------------
    Exception happened during processing of request from ('50.15.244.85', 2850)
    Traceback (most recent call last):
      File "/home/ubuntu/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/httpserver.py", line 1068, in process_request_in_thread
        self.finish_request(request, client_address)
      File "/usr/lib/python2.6/SocketServer.py", line 320, in finish_request
        self.RequestHandlerClass(request, client_address, self)
      File "/usr/lib/python2.6/SocketServer.py", line 615, in __init__
        self.handle()
      File "/home/ubuntu/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/httpserver.py", line 442, in handle
        BaseHTTPRequestHandler.handle(self)
      File "/usr/lib/python2.6/BaseHTTPServer.py", line 329, in handle
        self.handle_one_request()
      File "/home/ubuntu/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/httpserver.py", line 437, in handle_one_request
        self.wsgi_execute()
      File "/home/ubuntu/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/httpserver.py", line 287, in wsgi_execute
        self.wsgi_start_response)
      File "/home/ubuntu/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/urlmap.py", line 203, in __call__
        return app(environ, start_response)
      File "/home/ubuntu/src/mediagoblin/eggs/Beaker-1.5.4-py2.6.egg/beaker/middleware.py", line 152, in __call__
        return self.wrap_app(environ, session_start_response)
      File "/home/ubuntu/src/mediagoblin/mediagoblin/app.py", line 141, in __call__
        return controller(request)(environ, start_response)
      File "/home/ubuntu/src/mediagoblin/mediagoblin/auth/views.py", line 160, in verify_email
        user=request.user['username'])
    TypeError: 'NoneType' object is unsubscriptable
    ----------------------------------------

Add configuration options for SMTP connection.