title: Filtering by custom date range in Django admin
body: <p>Can Django admin site select entries by a custom date range, i.e. using two <code>DateFields</code> with <code>AdminDateWidget</code>? I know that there are <code>date_hierarchy</code> and <code>list_filter</code> properties, but they don't seem very useful when there are a lot of DB entries and you just need to filter items by exact <code>date__gte</code> and <code>date__lte</code> query.</p>