Sorting on all series views is now working

New: Sorting is now persisted on a per page and browser basis
New: Series lists now support sorting on all views

src/UI/Shared/Toolbar/ButtonModel.js

@@ -1,13 +1,29 @@
 'use strict';
 define(
     [
+        'underscore',
         'backbone'
-    ], function (Backbone) {
+    ], function (_, Backbone) {
         return Backbone.Model.extend({
             defaults: {
                 'target' : '/nzbdrone/route',
                 'title'  : '',
                 'active' : false,
-                'tooltip': undefined        }
+                'tooltip': undefined
+            },
+
+            sortValue: function () {
+                var sortValue = this.get('sortValue');
+                if (_.isString(sortValue)) {
+                    return this[sortValue];
+                }
+                else if (_.isFunction(sortValue)) {
+                    return sortValue;
+                }
+
+                return function (model, colName) {
+                    return model.get(colName);
+                };
+            }
         });
     });