emberjs/ember.js — pull request #2819 by johnny (2013-06-12 06:27:49+00:00)
Title: Ember.SortableMixin: new option sortFunction

Easily override sorting behavior by providing a custom sortFunction.

I had to redefine the whole orderBy function to get what I want. Older discussions regarding this seem to have died (#1216) or are going into a different direction (#1562).