Refactor the users class into their own files, add a common base class for federated users and add a verify_credentials method which only does the verification, without the linking. We use this in the superuser verification pass

data/users/database.py

@@ -0,0 +1,18 @@
+from data import model
+
+class DatabaseUsers(object):
+  def verify_credentials(self, username_or_email, password):
+    """ Simply delegate to the model implementation. """
+    result = model.user.verify_user(username_or_email, password)
+    if not result:
+      return (None, 'Invalid Username or Password')
+
+    return (result, None)
+
+  def verify_and_link_user(self, username_or_email, password):
+    """ Simply delegate to the model implementation. """
+    return self.verify_credentials(username_or_email, password)
+
+  def confirm_existing_user(self, username, password):
+    return self.verify_credentials(username, password)
+