- Properly display chained exceptions (PEP-3134).
- Rewrite celery integration to monkeypatch instead of using signals due to bugs in Celery 3's signal handling. The Celery scope is also now available in prerun and postrun signals.
- Fix Tornado integration to work with Tornado 6.
- Do not evaluate Django `QuerySet` when trying to capture local variables. Also an internal hook was added to overwrite `repr` for local vars.