Add rotate-left button to bitmap editor toolbar

core/modules/editor/operations/bitmap/rotate-left.js

@@ -0,0 +1,24 @@
+/*\
+title: $:/core/modules/editor/operations/bitmap/rotate-left.js
+type: application/javascript
+module-type: bitmapeditoroperation
+
+Bitmap editor operation to rotate the image left by 90 degrees
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+exports["rotate-left"] = function(event) {
+	// Rotate the canvas left by 90 degrees
+	this.rotateCanvasLeft();
+	// Update the input controls
+	this.refreshToolbar();
+	// Save the image into the tiddler
+	this.saveChanges();
+};
+
+})();