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```.
The purpose of the loop is to avoid having two ```if hasattr()``` calls. We can't include them in the list since ```apps``` doesn't exist for < 1.7 and ```shortcuts``` was removed in 1.7.