Update from 3.1 series

Unfortunately, since version 3.1.2 the CHANGELOG in master hasn't been updated with current versions. Additionally, there were two bug fixes only present in the stable series.

aleksis/core/migrations/0047_add_room_model.py

@@ -25,7 +25,7 @@ class Migration(migrations.Migration):
         recorder = migrations.recorder
         applied = False
         try:
-            applied = recorder.MigrationRecorder.Migration.objects.filter(app="core", name="0046_add_room_model").exists()
+            applied = recorder.MigrationRecorder.Migration.objects.filter(app="core", name="0047_add_room_model").exists()
         except ProgrammingError:
             applied = False
         if not applied: