[Do not merge] Remove django-cache-machine part I.

Stop using the magical caching manager.

I couldn't remove the dependency because we are using it for the CACHING backend (`{'default': {'BACKEND': 'caching.backends.memcached.CacheClass'...`). I think we can get those changed to use the one that ships with django.

f? Should we give it a try tomorrow morning and see what happens to our performance?