RESTful refactoring for course_info updates and handouts.

html page and update access use 2 different urls
GET update can get an individual update
STUD-944

cms/static/js/collections/course_update.js

@@ -4,7 +4,7 @@ define(["backbone", "js/models/course_update"], function(Backbone, CourseUpdateM
         collection of updates as [{ date : "month day", content : "html"}]
     */
     var CourseUpdateCollection = Backbone.Collection.extend({
-        url : function() {return this.urlbase  + "course_info/updates/";},
+        // instantiator must set url
 
         model : CourseUpdateModel
     });

cms/static/js/models/module_info.js

@@ -1,6 +1,6 @@
 define(["backbone"], function(Backbone) {
     var ModuleInfo = Backbone.Model.extend({
-      url: function() {return "/module_info/" + this.id;},
+      urlRoot: "/xblock",
 
       defaults: {
         "id": null,