title: possible to sort using orderby with property value?
body: <p>think of a todo list's item has level of urgent, and it can be set by the user. The priority level has index of 1,2,3.. I want to sort the item within ng-repeat.</p>
  
  <p>and I want the high to be the top always, I'm using push.</p>
  
  <p>here is the demo of my app
  <a href="http://plnkr.co/edit/Ivo4EvtKEZ765waXFFRV?p=preview" rel="nofollow">http://plnkr.co/edit/Ivo4EvtKEZ765waXFFRV?p=preview</a></p>