Include django contrib in stack 505

The list for ```HIDE_IN_STACKTRACE``` is rather long now and it has to be manually edited if modules are added/removed to Django. We could potentially programmatically loop through the modules of ```django```.
I understand, but why do you want `apps` and `shortcuts` present only if they are present in django? `HIDE_IN_STACKTRACES` just an ignore list, isn't it?