gregbell/active_admin — pull request #2432 by dedsm (2013-08-21 19:08:09+00:00)
Title: making sort_order accept multiple fields

now config.sort_order will accept sorting by multiple fields,
the format is "field1_(asc|desc), field2_(asc|desc)" preserved backwards
compatibility

Issue https://github.com/gregbell/active_admin/issues/659