Make db.migrations ignore South-style migrations.

django/db/migrations/loader.py

@@ -82,9 +82,18 @@ class MigrationLoader(object):
                         migration_names.add(import_name)
             # Load them
             for migration_name in migration_names:
+                try:
                     migration_module = import_module("%s.%s" % (module_name, migration_name))
+                except ImportError as e:
+                    # Ignore South import errors, as we're triggering them
+                    if "south" in str(e).lower():
+                        continue
+                    raise
                 if not hasattr(migration_module, "Migration"):
                     raise BadMigrationError("Migration %s in app %s has no Migration class" % (migration_name, app_label))
+                # Ignore South-style migrations
+                if hasattr(migration_module.Migration, "forwards"):
+                    continue
                 self.disk_migrations[app_label, migration_name] = migration_module.Migration(migration_name, app_label)
 
     def get_migration_by_prefix(self, app_label, name_prefix):