create celltoolbar in cell.js and inherit

IPython/frontend/html/notebook/static/js/cell.js

@@ -50,7 +50,9 @@ var IPython = (function (IPython) {
      * and will be called by Base Class constructor.
      * @method create_element
      */
-    Cell.prototype.create_element = function () {};
+    Cell.prototype.create_element = function () {
+        this.celltoolbar = new IPython.CellToolbar(this);
+    };
 
 
     /**

IPython/frontend/html/notebook/static/js/codecell.js

@@ -58,7 +58,7 @@ var IPython = (function (IPython) {
 
     /** @method create_element */
     CodeCell.prototype.create_element = function () {
-        this.celltoolbar = new IPython.CellToolbar(this);
+        IPython.Cell.prototype.create_element.apply(this, arguments);
 
         var cell =  $('<div></div>').addClass('cell border-box-sizing code_cell vbox');
         cell.append(this.celltoolbar.element);

IPython/frontend/html/notebook/static/js/textcell.js

@@ -42,8 +42,8 @@ var IPython = (function (IPython) {
      * @private
      */
     TextCell.prototype.create_element = function () {
+        IPython.Cell.prototype.create_element.apply(this, arguments);
         var cell = $("<div>").addClass('cell text_cell border-box-sizing vbox');
-        this.celltoolbar = new IPython.CellToolbar(this);
         cell.append(this.celltoolbar.element);
         cell.attr('tabindex','2');
         var input_area = $('<div/>').addClass('text_cell_input border-box-sizing');