Fix up some SAML issues

* Fix an issue I created overriding authenticate
* Fix up attribute mapping using an identity provider class.  The
  methods built into django-social-auth for saml are probably not going
  to work.  We also now expose those mappings in a settings attrs map
  that the user can override.

awx/sso/middleware.py

@@ -22,8 +22,6 @@ from awx.main.models import AuthToken
 class SocialAuthMiddleware(SocialAuthExceptionMiddleware):
 
     def process_request(self, request):
-        request.META['SERVER_PORT'] = 80 # FIXME
-
         token_key = request.COOKIES.get('token', '')
         token_key = urllib.quote(urllib.unquote(token_key).strip('"'))