Expose and use get requests specifying type in the JS

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

@@ -2102,6 +2102,7 b' define(['
         this.notebook_name = utils.url_path_split(this.notebook_path)[1];
         this.events.trigger('notebook_loading.Notebook');
         this.contents.get(notebook_path, {
+            type: 'notebook',
             success: $.proxy(this.load_notebook_success, this),
             error: $.proxy(this.load_notebook_error, this)
         });

IPython/html/static/services/contents.js

@@ -87,6 +87,9 b' define(['
             error : this.create_basic_error_handler(options.error)
         };
         var url = this.api_url(path);
+        if (options.type) {
+            url += '?type=' + options.type;
+        }
         $.ajax(url, settings);
     };
 
@@ -250,20 +253,11 b' define(['
      *     last_modified: last modified dat
      * @method list_notebooks
      * @param {String} path The path to list notebooks in
-     * @param {Function} load_callback called with list of notebooks on success
-     * @param {Function} error called with ajax results on error
+     * @param {Object} options including success and error callbacks
      */
     Contents.prototype.list_contents = function(path, options) {
-        var settings = {
-            processData : false,
-            cache : false,
-            type : "GET",
-            dataType : "json",
-            success : options.success,
-            error : this.create_basic_error_handler(options.error)
-        };
-
-        $.ajax(this.api_url(path), settings);
+        options.type = 'directory';
+        this.get(path, options);
     };