Fix constructor comments

Add content_manager as a dictionary key to the options param passed in to the NotebookList and Notebook constructors.

IPython/html/static/notebook/js/notebook.js

@@ -50,6 +50,7 @@ define([
         //      Dictionary of keyword arguments.
         //          events: $(Events) instance
         //          keyboard_manager: KeyboardManager instance
+        //          content_manager: ContentManager instance
         //          save_widget: SaveWidget instance
         //          config: dictionary
         //          base_url : string

IPython/html/static/tree/js/notebooklist.js

@@ -20,6 +20,7 @@ define([
         //          element_name: string
         //          base_url: string
         //          notebook_path: string
+        //          content_manager: ContentManager instance
         var that = this;
         this.session_list = options.session_list;
         // allow code re-use by just changing element_name in kernellist.js