Bring back _class names, since code minification breaks reliance on constructor.name.

Closes #248.

src/ui/CanvasView.js

@@ -16,6 +16,8 @@
  * @private
  */
 var CanvasView = View.extend(/** @lends CanvasView# */{
+	_class: 'CanvasView',
+
 	/**
 	 * Creates a view object that wraps a canvas element.
 	 *