Optimize query count in notification.views.notices

[zsiciarz]

Currently the notices() view does not retrieve notice types together with notices for current user. If the template processes each notice like below:

{% for notice in notices %}
  {{ notice.notice_type.display }}
{% endfor %}

each notice_type is fetched separately from the database. When the user is displayed a lot of notifications, query count will quickly increase. I propose a patch to optimize away most of these queries by using select_related() in the view function.

Patch: http://gist.github.com/429952