Remove middleware component, since we're not using it anymore.

django_openidconsumer/middleware.py

-class OpenIDMiddleware(object):
-    """
-    Populate request.openid and request.openids with their openid. This comes 
-    eithen from their cookie or from their session, depending on the presence 
-    of OPENID_USE_SESSIONS.
-    """
-    def process_request(self, request):
-        request.openids = request.session.get('openids', [])
-        if request.openids:
-            request.openid = request.openids[-1] # Last authenticated OpenID
-        else:
-            request.openid = None