User user IDs instead of email addresses for profile keys, since they're permanent.

lib/session.py

@@ -23,10 +23,10 @@ from cosmopolite.lib import models
 def CreateClientAndProfile(client_id, google_user):
   if google_user:
     # We're going to need a profile for this user regardless
-    profile = models.Profile.get_by_key_name(str(google_user))
+    profile = models.Profile.get_by_key_name(google_user.user_id())
     if not profile:
       profile = models.Profile(
-          key_name=str(google_user), google_user=google_user)
+          key_name=google_user.user_id(), google_user=google_user)
       profile.put()
   else:
     profile = None