Change codebase to query or create correct User model

The code base had many references to User.username and other
specific to LocalUser attributes as that was the way it use to exist.
This updates those to query on the generic User model but filtering
by attributes on the LocalUser.

mediagoblin/auth/tools.py

@@ -23,7 +23,7 @@ from sqlalchemy import or_
 
 from mediagoblin import mg_globals
 from mediagoblin.tools.crypto import get_timed_signer_url
-from mediagoblin.db.models import User, Privilege
+from mediagoblin.db.models import LocalUser, Privilege
 from mediagoblin.tools.mail import (normalize_email, send_email,
                                     email_debug_message)
 from mediagoblin.tools.template import render_template
@@ -106,9 +106,9 @@ def send_verification_email(user, request, email=None,
 
 
 def basic_extra_validation(register_form, *args):
-    users_with_username = User.query.filter_by(
+    users_with_username = LocalUser.query.filter_by(
         username=register_form.username.data).count()
-    users_with_email = User.query.filter_by(
+    users_with_email = LocalUser.query.filter_by(
         email=register_form.email.data).count()
 
     extra_validation_passes = True
@@ -190,7 +190,7 @@ def no_auth_logout(request):
 
 
 def create_basic_user(form):
-    user = User()
+    user = LocalUser()
     user.username = form.username.data
     user.email = form.email.data
     user.save()