Move all order logic to models

- Have a default order for each model
-- The overall default is ID DESC
- Allow for custom orderings
-- When comma-separated IDs are used

app/controllers/artist_commentary_versions_controller.rb

@@ -2,7 +2,7 @@ class ArtistCommentaryVersionsController < ApplicationController
   respond_to :html, :xml, :json
 
   def index
-    @commentary_versions = ArtistCommentaryVersion.search(params[:search]).order("artist_commentary_versions.id desc").paginate(params[:page], :limit => params[:limit])
+    @commentary_versions = ArtistCommentaryVersion.search(params[:search]).paginate(params[:page], :limit => params[:limit])
     respond_with(@commentary_versions) do |format|
       format.xml do
         render :xml => @commentary_versions.to_xml(:root => "artist-commentary-versions")