gregbell/active_admin — pull request #1011 by DMajrekar (2012-02-14 11:53:00+00:00)
Title: Allow the default sorting to be set on individual resources

Example usage:

```ruby
ActiveAdmin.register Post do
default_sort :title_asc
end
```

NOTE: This was originally submitted in #922. This has now been updated and tested on ruby 1.8.7 / 1.9.2 / 1.9.3