Enable the cached_db session engine by default

This will work out well when using memcached in production, and should just
fall back to using the DB when developing locally with no cache or any other
sort of caching.

Signed-off-by: Dan McGee <dan@archlinux.org>

settings.py

@@ -89,6 +89,8 @@
 
 MESSAGE_STORAGE = 'django.contrib.messages.storage.session.SessionStorage'
 
+SESSION_ENGINE = 'django.contrib.sessions.backends.cached_db'
+
 INSTALLED_APPS = (
     'django.contrib.auth',
     'django.contrib.contenttypes',
@@ -109,4 +111,3 @@
 )
 
 # vim: set ts=4 sw=4 et:
-