Make Contents.new more generic

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

@@ -89,8 +89,8 b' define(['
         this.element.find('#new_notebook').click(function () {
             // Create a new notebook in the same path as the current
             // notebook's path.
-            that.contents.new_notebook(that.notebook.notebook_path,
-                {
+            that.contents.new(that.notebook.notebook_path, null, {
+                    ext: ".ipynb",
                     success: function (data) {
                         window.open(
                             utils.url_join_encode(

IPython/html/static/services/contents.js

@@ -97,12 +97,23 b' define(['
      *
      * @method scroll_to_cell
      * @param {String} path The path to create the new notebook at
+     * @param {String} name Name for new file. Chosen by server if unspecified.
+     * @param {Object} options:
+     *      ext: file extension to use if name unspecified
      */
-    Contents.prototype.new_notebook = function(path, options) {
-        var error = options.error || function() {};
+    Contents.prototype.new = function(path, name, options) {
+        var method, data;
+        if (name) {
+            method = "PUT";
+        } else {
+            method = "POST";
+            data = JSON.stringify({ext: options.ext || ".ipynb"});
+        }
+
         var settings = {
             processData : false,
-            type : "POST",
+            type : method,
+            data: data,
             dataType : "json",
             success : options.success || function() {},
             error : this.create_basic_error_handler(options.error)

IPython/html/static/tree/js/main.js

@@ -60,8 +60,8 b' require(['
     login_widget = new loginwidget.LoginWidget('#login_widget', common_options);
 
     $('#new_notebook').click(function (e) {
-        contents.new_notebook(common_options.notebook_path,
-            {
+        contents.new(common_options.notebook_path, null, {
+                ext: ".ipynb",
                 success: function (data) {
                     window.open(
                         utils.url_join_encode(